He is the son of Greg Universe and Rose Quartz, and the only male member of the Crystal Gems. A half-human, half-Gem as a result of his parentage, Steven is an extraordinary unique being with latent powers beyond that of both normal humans and Gems. Guided and aided by the Crystal Gems, Steven's destiny is to protect humanity as his mother did before him.
Steven is relatively short with a thick build. He has curly, dark brown hair and black irises. He wears a reddish-pink T-shirt with a yellow star on it. He also wears blue jeans and reddish-pink sandals. His gem, a rose quartz which he inherited from his mother, is where his belly button should be.
He is a super-excitable, hammy kid.
Steven is an amicable, outgoing and carefree boy with a happy-go-lucky attitude that is appreciated by many of the citizens of Beach City in one way or another. He is musically inclined, a trait he has inherited from his father, with a propensity for breaking out into song and (occasionally) playing on his ukulele. Likewise, Steven is very kindhearted and compassionate to the people around him, something which Pearl notes he has inherited from his mother. He is friendly toward almost everyone he meets, rarely holds grudges, and is very non-discriminatory, never treating anyone with prejudice. No matter the situation, Steven cares deeply for his friends and family, even risking his life for them, and will try helping others before resorting to violence.
Steven looks up to his caretakers -- Garnet, Amethyst, and Pearl -- and considers them his family. He wants to be a great hero just like them, and is eager to go on adventures with the trio, both to prove his worth, and to have fun exploring strange lands. Despite his undeveloped magical power and lack of experience, he has proven himself to have much heroic potential through his resourcefulness, optimism, and confidence.
Steven is rather naïve and socially oblivious, due to his isolated upbringing by the Gems. He is often prepared to go on adventures at a moment's notice, but has a habit of biting off more than he can chew, requiring the Gems to intervene. With his unique way of handling problems, he tends to make situations worse before he makes them better. For a while, despite experiencing near-death or traumatizing events, Steven would retain his child-like innocence and obliviousness to the dangers. Following the revelations of the Gems' dark history and the encounter with Jasper though, Steven has gained a new level of seriousness about the dangers of being a Crystal Gem. This initially made Steven self-conscious about his immaturity and he restored to outgrow it, though his misguided attempt would be a source of self-inflicted misery as he tried to break off his friendship with Connie to protect her from harm; it was only Connie's sensible nature that stopped him from going down a bad road.
Like his mother, he appears to be very charismatic, easing a raging crowd (in "Political Power"), motivating his friends and father in working out and Pearl to find strength to fight Sugilite (in "Coach Steven").
But the truth is, we rely on you. Your voice inspires us, binds us, reminds us why we promised to protect the planet. You need to be that voice, for them.
|—Garnet to Steven in "The Return"|
Being half-human and half-Gem, it is unknown if he possesses all the abilities of a pure Gem, such as retreating to their gemstone when taking fatal damage. Steven has shown the abilities of a regular Gem such as to shape shift or summon his weapon (a shield), but has little control of them due to him not having enough training. He can also warp using the warp pads, and bubble objects and gemstones to be teleported to the temple with seemingly full control.
Due to having his mother's gemstone, he shares most of his unique abilities with her.
- Augmented Weapon Summoning: Shield Steven has, on multiple occasions, summoned his shield in the form of a incredibly durable bubble which encases Steven and whoever he's protecting. For whatever reason, Steven was shown able to utilize this ability much better than summoning the shield itself in its original weapon form. It should also be noted that he can shoot his shield, as shown In Gem Glow.
- Age Manipulation: In the episode "So Many Birthdays," Steven discovers he can manipulate his age through his state of mind and maturity. Steven's biological age depends solely on how old he thinks he is.
- Healing: (currently inactive): Steven's saliva has the power to heal the injuries of both humans and Gems. Steven's healing capabilities have not yet been seen to the full extent of his power, but he is shown to be capable of healing the cracked gemstones as seen when he healed Lapis Lazuli in "Ocean Gem." He can also heal common human injuries, seen when he healed Connie's eyesight in "An Indirect Kiss" and Greg's broken leg in "House Guest."
- Phytokinesis: In "Watermelon Steven," Steven discovers he has the ability to grow sentient flora in the form of watermelons shaped like himself. They acted as his bodyguards, but they weren't directly under his control and the Watermelon Stevens would ignore his orders and attacked whoever they thought was threatening him, suggesting that he doesn't have full mastery over this ability thus far.
- Superhuman Strength: Steven occasionally performs feats of strength that would be impossible for a human boy his age -- or even a grown man. In "Together Breakfast," Steven is able to lift and force the Together Breakfast in its mutated state into the lava pool by himself without the other Crystal Gems. He also displays a large amount of strength in "Arcade Mania" when he rips off the top of the Meat Beat Mania arcade game to break Garnet from her trance. He displays an even further amount of strength in "The Return" when he smashes Greg's van's dashboard with a single punch, apparently hard enough to both shatter it and activate the airbags. In "Joy Ride" he's able to move Jenny away from the escape pod without any effort. As Gems are much stronger and durable than their appearance would indicate, Steven's superhuman strength was most likely passed down to him from his mother.
|Steven wears a large pink coat with his jeans and sandals.||"Arcade Mania"|
|Steven wears a hoodie roughly the same color as his shirt with his jeans and sandals.||"Steven the Sword Fighter"|
|Steven wears a tanktop that resembles his usual shirt, but with a bright yellow outline along the edges instead. He also has his pants and sandals.||"Beach Party"|
|Steven wears a large farmer’s hat, overalls, and he also has a stick if hay in his mouth as well.||"Watermelon Steven"|
|Steven wears a red, white, and blue head ban with mirrored shades, a sleeveless t-shirt with shorts and sandals.||"Coach Steven"|
|Steven wears a large sheet made to look like a snake, and he also wears boots with claws on them for extra details.||"Keep Beach City Weird"|
|Steven wears light green pajamas and pants.||"Lion 3: Straight to Video"|
|Steven wears a hoodie roughly the same color of his shirt with his jeans tucked into rubber boots with ducks on them.||"Frybo"|
|Steven wears a large rainbow wig with white face paint with red around his mouth with a big red nose, a very large sleeveless shirt, jeans, and green sandals.||"So Many Birthdays"|
|Steven wears a torn, muddy, wet shirt with a pile of leaves tied around his waist instead of his pants. He also is barefoot.||"Island Adventure"|
|Steven wears his pink sweatshirt with jeans and sandals and a hat that covers almost all of his face.||"Secret Team"|
Rose is Steven's mother, although he never met Rose face to face since she gave up her physical form to create him, and he's grown up only hearing about her. Steven seems to have mixed feelings about Rose. In "An Indirect Kiss," he states "I don't know how to feel about you, but everyone else does. I wish I could have met you, then this place would make me sad, and I could cry healing tears, like you." Although he does jump to her defense in "Lars and the Cool Kids" when Lars called her weird, Steven snaps at him, ending his outburst with "she saw beauty in everything...even in jerks like you!" He also seemed very touched upon finding the video she left for him in "Lion 3: Straight to Video."
Greg Universe is Steven's father. As seen in "Laser Light Cannon" and "Cat Fingers," they share a strong father-to-son bond and Greg is always emotionally supportive. Although Greg does not live with Steven, they often hang out. In "House Guest," it is shown that Steven and his father used to lived together, but as Steven grew older he moved in with the Crystal Gems in order for them to teach him about "magical Gem stuff" - something which his father could not do. However even though Greg knows that Steven is safe in the Crystal Gems care, he is still slightly apprehensive about Steven going on missions and getting involved in "Gem stuff".
Pearl acts more motherly to Steven than the other Crystal Gems do, as whenever he's in a possibly dangerous situation, she usually panics and acts first to protect him. Likewise, Steven seems to think of Pearl as a motherly figure as well, nearly crying at her defeat in "Steven the Sword Fighter" and keeping a framed photo of her in "Monster Buddies." Pearl has mixed feelings for Steven deep down; while she cares deeply for Steven she also misses his mother, Rose Quartz, very much as they were very close to each-other when she was alive. She sees much of his mother that he becomes a constant reminder of Rose which both gladdens and saddens Pearl. These feelings come to the surface in "Rose's Scabbard" where the revelation that Rose had apparently kept secrets from Pearl, her closest friend and confidant, causes Pearl to break down mentally and run away from Steven and the other Crystal Gems. When Steven pursues her she shows signs of resentment towards him, and Lion, which culminates in her apparent inaction when Steven misses a jump and almost falls to his doom. The two reconcile at the end of the episode, but as revealed in "Joy Ride" Steven no longer feels comfortable talking about the subject of his mom with the other Crystal Gems as he has grown to feel that they blame him for her not being around anymore.
Amethyst acts like an older sister to Steven, often joking around with him and joining him in his misadventures. Pearl will often scold Amethyst for being too reckless with Steven when she misleads him such as in "Cat Fingers," which Amethyst admits is probably accurate. Steven seems to acknowledge Amethyst's reckless nature, calling her out when she didn't help him in "Joking Victim" and worrying for her safety in "An Indirect Kiss."
Garnet acts more like a mentor towards Steven, always encouraging him and setting a good example. It is shown that Steven respects her as he always listens whenever she speaks. Steven usually asks Garnet for permission before anyone else, as shown in "Monster Buddies." As shown in the beforementioned episode, Garnet is usually open to letting Steven attempt things that Pearl may not, indicating that she has more trust in him than Pearl. Despite her stoic and somewhat distant nature, the two share an occasionally close and emotional relationship; in "Future Vision" she inadvertently freaks out and endanger him by revealing her "future vision" to him- which she did only because she thought he'd understand and it would bring them closer. Immediately after Sapphire and Ruby's re-fusion in "Jail Break" Garnet acts a lot more emotional and loving towards Steven, indicative of the deep, true love that she has for him that her pre-regeneration self wouldn't, or couldn't, express.
Oh Steven. We already love you.
|—Garnet confirming Ruby and Sapphire's feelings toward Steven|
Little is known about the relationship between Steven and the two halves of Garnet, but since Garnet is a Fusion Gem of the two it can be assumed that their individual feelings for Steven are similar to, if not the same as, Garnet's feelings for him.
Sadie is one of Steven's friends who, unlike her co-worker Lars, is friendly, considerate and affectionate towards Steven. In "Joking Victim," Steven helps Sadie by working at the Big Donut. Steven also helps Sadie to strengthen her relationship with Lars in "Island Adventure."
Connie is one of Steven's friends whom he saved in "Bubble Buddies" from a falling rock by using his gem to summon his bubble. He is initially very awkward and nervous to talk with her, but their friendship has grown and presently, they appear to be close friends. In "Lion 2: The Movie," they are shown casually hanging out. Steven appears to have a crush on Connie, though it has not been discussed in the show. In "An Indirect Kiss," Steven and Connie almost kissed, as referred to by the title. He also genuinely cares about Connie's safety and well being as seen in "Winter Forecast," as well as in "Full Disclosure." In "Open Book" Steven is heavily implied to have a crush on Connie, and was afraid to tell her his opinion about the ending of the final Unfamiliar Familiar book because he was afraid of her disliking him for it.
Lion is Steven's "pet" lion whom he discovers in "Steven's Lion" while the Crystal Gems went to retrieve the desert glass. He has some sort of connection with Steven and his gem as he is the only one who can go into Lion's pocket dimension and put stuff inside there aside from Rose Quartz. Lion, most of the time, does whatever he wants and often ignores or disobeys Steven. Lion is also seen to be caring towards Steven as well as being aware of Steven's needs, like when Lion kept lying on Steven's head to show Steven his pocket dimension where it contained, among other things, a video left by Rose Quartz for Steven, after he said he wanted to know more about her in "Lion 3: Straight to Video."
Onion is Steven's friend whom he talks to in the episode "Bubble Buddies." Steven addresses Onion as if they're good friends. In "Onion Trade," Steven gives his favorite action figure to him as a gift, despite the fact that Onion had originally stolen it. When they're not together, Steven expresses some confusion as to who and what Onion is, being unsure if he's even human in "Marble Madness."
Lars appears to be annoyed by Steven. He's always making fun of him, although this may only be because he is jealous of Steven for being a Crystal Gem. Steven may be ignorant of this however, because in "Bubble Buddies," he refers to Lars as his 'BFF.' However, in "Lars and the Cool Kids," he became angry with Lars and called him a jerk for insulting his mother. As of "Lars and the Cool Kids," Lars and Steven find a way to connect and Lars is seemingly on better terms with Steven. In some ways, Steven looks up to Lars, and was excited at the chance of being able to receive a high-five from him in "Future Vision." However, Steven doesn't hesitate to call out Lars on his bad behavior at times.
Steven became friends with her in "Mirror Gem" when he was given the mirror by Pearl, which turned out to not work. Then a little while later, Lapis began to talk to Steven and they became good friends, with Steven calling them "Beach Summer Fun Buddies", a nickname to which Lapis agreed. She wanted to get out of the mirror and told Steven how to do so. After she was free, she warns Steven not to trust the Crystal Gems and walks away. In "Ocean Gem," Steven healed Lapis' gem crack, which in result, gave her eyes and wings back. She thanks Steven before departing back to her home planet. In "The Message," Steven defends her, and sings a song all about her and the previous events. Later, Lapis gives Steven a message, she addresses him specifically. In "Jail Break," Lapis fuses with Jasper, forming Malachite, as a way to save Steven.
Steven doesn't really know how to feel about Peridot, but he seems to have wanted to befriend her in "Marble Madness", approaching her without fear and even trying to have a friendly conversation with her. Of course, this didn't go as well as he hoped and almost got crushed by her. Despite this, he still believes she can be good and even said that maybe if she sees humans she might not want to hurt anyone.
- Steven's name and appearance is based on Rebecca Sugar's brother, Steven Sugar, who is a background artist for the show.
- He is the first and only male Gem so far in the series.
- He is also the first and only Gem with a defining gender.
- Steven is the only Gem that is not named after his gem, most likely because he is half human or because his gem, a rose quartz, was his mother's gem and name.
- Steven's middle name however (Quartz), represents Rose Quartz.
- In the transition from the pilot to the series, Steven underwent only one significant change, with it being the removal of the gold ring around his gem.
- Steven is going to soon be able to be trusted fully by the gems and not over-protected. 
- Steven is home-schooled by the Gems. 
- Steven is the only and first half-human, half-Gem to exist in the series. 
- Steven is the only Crystal Gem that doesn't have a color scheme that matches his gem.
- This could be because he is part human, or he inherited his mother's skin.
- His skin tone is; however, a lighter pink tone than nearly every other pink-skinned characters in the show.
- The rose quartz on Steven is faceted with a pentagonal shape.
- Steven, along with Sugilite and Jasper, is the only Gem whose gemstone is not a birthstone.
- In "Together Breakfast," he had a phone similar to an iPhone, but Garnet snatched it from him to destroy it after he took a picture of the Evil Scroll.
- However, in "House Guest" a new phone can be seen on his nightstand.
- In "Together Breakfast," Steven seems to be surprisingly strong, as he was the only one to defeat the Together Breakfast in its mutated state by himself without the other Crystal Gems. He also displays a large amount of strength in "Arcade Mania" when he rips off the top of the Meat Beat Mania arcade game to break Garnet from her trance. He displays an even further amount of strength in "The Return" when he smashes Greg's van's dashboard with a single punch, apparently hard enough to both shatter it and activate the airbags. In "Joy Ride" he's able to move Jenny away from the escape pod without any effort.
- Surprisingly strong for a human, yes, but not for a Gem. Their human constructs are much stronger than their physical appearance would imply. It is not surprising Steven would have some form of "super strength" being a Half-Gem.
- In "So Many Birthdays," his adult version of himself is similar to Rebecca Sugar's brother, Steven Sugar.
- On the topic of age, Steven's exact age has not yet been confirmed.
- Steven's shield has appeared four times throughout the series: once in "Gem Glow," a second time in "Ocean Gem," a third time in "The Return," and a fourth time in "Say Uncle."
- It was revealed in "Monster Buddies" that Steven keeps a framed picture of Pearl on the side of his fridge. However, it was destroyed by the Centipeetle Mother.
- He is the character who cried more times than any other character in the series.
- Steven is the only character to appear in every episode so far.
- It's shown in the episode "Island Adventure" that Steven doesn't really understand the concept of privacy and personal space.
- In "Warp Tour," Steven is revealed to be allergic to pollen.
- In "Alone Together," Steven and Connie fuse together to form Stevonnie.
- Based on Pearl's reaction, it is still unknown if Steven can fuse with "full" Gems (as he is a Half-Gem).
- In "The Test," it is revealed that Steven's healing powers have stopped working. It is currently unknown if they can be reactivated or not. It is also unknown why they stopped working but it appears to be tied in Steven's confidence in his own abilities as when Greg pretended it didn't work on his broken leg, it seemingly stopped working for real.
- In "House Guest," a Sailor Moon manga book can be seen on Steven's nightstand.
- Steven's voice noticeably matures throughout the series, especially noticeable when compared from the earliest episodes to the latest.
- He is progressively getting better at handling his shield.
- He is able to summon his bubble shield when he needs to now.
- He is able to adjust the size of his shield, depending on the incoming threat and the party he's trying to protect.
- Steven is the only known person in town capable of calling political favors from Mayor Bill Dewey.
- He doesn't seem to be affected with the Homeworld technology weapons, such as the Gem Destabilizer, or their ship's jails as is shown in "Jail Break," probably because he is only a half-gem, half-human.
- In "Joy Ride," Steven reveals that he has become uncomfortable talking about his mom with the Crystal Gems because he feels that they blame him for her not being around.
- It's stated by Ian Jones-Quartey that Rose shape-shifted a womb for Steven to be born from. 
- Steven has teddy bears, such as Master of Ceremonies Bear-Bear and Sir Bearington.
- Steven seems to like drawing as is shown in the episodes "Shirt Club", when he drew Greg, and "Open Book", when he drew a picture of a character of The Spirit Morph Saga.