Steven Anita Smith is the son of Francine and Stan Smith. Steve has an older sister Hayley. They reside at 1024 Cherry Street, Langley Falls, Virginia. The family also have a fish named Klaus and an alien named Roger.
Steve is an awkward 15 year old boy. He is a bit of a social outcast, but has three close friends. Steve and his friends spend a lot of time playing Dungeons and Dragons and pretending to be the characters from Star Trek. Steve is currently a student at Pearl Bailey High School.
He has only recently entered puberty which he is very proud of, and is always trying to lose his virginity or have a girlfriend. He is slightly overweight, as "There Will Be Bad Blood" reveals he has a slight gut and love handles.
Steve graduates from Arizona State University in "The Life and Times of Stan Smith" for answering a single question in science class, becoming valedictorian as well, during which his speech earns him a Ph.D and five Bud Ices.
- Roger is Steve's alien and very close friend. But they spend little time out of the house together as Roger is usually doing something immoral or illegal while out and about. Roger and Steve also play a detective duo called Wheels and the Legman in which Steve sits in a wheel chair but only after proving that he deserved it more by figuring out Roger's new partner was NOT in fact an angel due to the fact that she was eating devils food cake in "Haylias".
- Barry is an overweight evil genius, who takes tablets prescribed to him to stop his evil behavior. When he is taking his tablets he speaks with a squeaky accent and is fairly dim-witted. He has also spoken in a deep voice when referring to ladies, and has spoken in a Gary Oldman like English accent when in evil mode in "With Friends Like Steve's". He is also gifted as Rainman when it comes to counting cards as seen in "Home Wrecker".
- Snot has curly hair and acne. He and Steve are best friends as stated in "License to Till" when Snot calls all 3 guys his friends but whispers to Steve that he is "the best of the bests". He and Steve like older women, he once had an affair with Steve's girlfriend Gretchen in "Con Heir".
- Toshi is a Japanese boy who does not speak English, but seems to understand it. The others don't seem to understand what he says. He doesn't entirely like Steve and when he was once offered to kill Steve in "Finances With Wolves", he expressed it was his fondest wish. He also knows about Roger as an alien as he comments on the fact in "Bar Mitzvah Hustle".
- Debbie is Steve's main romance for numerous episodes.
- Betsy White is the gymnast daughter of Chuck and Christy White, by kissing her Steve effectively passes on Roger's baby and she is sent away, happy that she no longer has to do gymnastics in "Deacon Stan, Jesus Man".
- Svetlana is a Russian mail order bride in "Of Ice and Men" that Steve, Barry, Snot and Toshi share, until she eventually falls for Toshi.
- Becky Arangino was staff member on an ocean-liner in "The Vacation Goo" who was immensely attracted to younger men. When she and Smith family got stranded on an island, she was killed in a rockslide and then her body was eaten.
- Lindsay Coolidge is a girl from Steve's class, who agreed to date him because she wanted to help her friend Jewel get a date in "Francine's Flashback". Much her own surprise, she found herself enjoying Steve's company. Unfortunately she was forced to have her mind erased when she and Jewel discovered Roger was an alien.
- Lisa Silver a mean-spirited cheerleader who agreed to date Steve, solely out of a desire to leech off of Steve's power as School President in the pilot. After admitting the truth, Stan had her entire family deported.
- Amy is a girl Steve dreams of in his lucid dreams in "Merlot Down Dirty Shame". When Klaus and Hayley trick Steve into thinking he has a lucid dream he goes to school and kisses her making her become aroused. When Steve tries to fly out the window with Amy, Steve becomes injured and has her almost killed as he claimed that Amy's family charged him for attempted murder.
- Makeva is an African girl in "Camp Refoogee" Steve met when Stan sent him away to Summer Camp although it was in truth a Refugee Camp in Africa. Before they could attempt a relationship however, Makeva was kidnapped. Although Steve saved her in the end, Makeva suffered from Stockholm syndrome and had fallen in love with her kidnapper.
- Gretchen Grossbard, from "Con Heir". An 80-year-old lady Steve starts having a relationship with while coping over the death of his fake grandfather at his retirement community.
- Carmen Selectra an MTV reporter who came to broadcast Rogers Spring-Break party in "Spring Break-Up". Steve's high standards for his first-time impress her enough to have her breast implants removed just for him. Before anything can happen however a stage collapses upon her, crushing her to death. It is said with more 'padding' around her chest area, she may have survived.
- Phyllis, Stan's avatar from "Virtual In-Stanity". Stan used her to get closer to Steve but Steve thinks that Phyllis only wants to be his friend. Steve then falls for Chelsea but dumps Chelsea when Phyllis Promises to have sex with Steve. Francine finds out about Stan being Phyllis and tries to stop him and succeeds. Phyllis breaks up with Steve and they end up not having sex.
- Jeanine Winthrop, the girl of Steve's wet dreams in "A Jones for a Smith". She carries a desire for nerds and is attracted to Steve. While playing games at her house, Steve finds out that even her father is on board - once he meets Steve's parents. Desperate for a crack fix, Stan tries to steal from the family and then offers to perform an unnatural act on the father, ruining Steve's chances. On his way out, Jeanine demonstrates her flexibility, making things even more painful for Steve who says he will hate Stan until the day he dies.
- Ashley, a girl who is willing to have sex with Steve in "Stan's Food Restaurant", but ends up being insane, believing that her doll Julia is real. Desperate to get laid, Steve recruits Snot to act as Julie's date. However, Ashley ends up being too crazy and Steve is unable to put up with her when she takes the Julie bit too far.
- Chelsea is a nerdy girl who was attracted to Steve in "Virtual In-Stanity", yet Steve was not attracted to her as he was in love with Phyllis. When Steve thinks Phyllis does not love him, He becomes attracted to Chelsea. When Phyllis tells Steve he will have sex with him, He dumps Chelsea. In the end when Steve tries to get back with her, she rejects him.
- Reshma, from "License to Till" is hit by Steve in an attempt to get popular. Though this backfires, she kisses him at the party and promises him first chance at her breasts when they mature.
- Akiko Yoshida: Although Steve himself had shown an interest in her as far back as "Weiner of Our Discontent", she had rejected him for another in "Best Little Horror House in Langley Falls". In "Spelling Bee My Baby", she finally falls for him when they both come under pressure from their respective mothers to win the National Spelling Bee and they share a kiss at The Langley Falls. Although Francine kidnaps Akiko and plants a note to make Steve think she dumped him, they fall for each other again at the spelling bee and both refuse to allow themselves to win, intentionally misspelling words to keep the other in the match.
Although Steve tries his best to come off as a very confident person, he is deep down a teen who suffers with a great deal of self-esteem issues. The core of these issues most likely comes from his father, Stan, who in an attempt to make Steve exactly like himself, verbal and psychological abuses Steve by diminishing his self-worth. As a result, Steve unlike his sister Hayley hungers for his father's approval, often to the point of being sycophantic. In hopes of getting Stan's approval, Steve will at times mimic Stan's xenophobic Right-Wing Republican beliefs, not so much because he believes in them himself, but because Stan tells him he should believe in them with no other option.
There are however points where Steve's confidence and self-worth wins out over Stan's demands and he becomes willing to rebel and stand up to his father. For example, in "Star Trek", where Steve, tired of being lied to and used by Stan, divorces his entire family. In "Bully for Steve", Steve handles his dad's bullying by hiring Stan's childhood bully Stelio Kontos to beat him up rather than face him directly, as Stan had wanted.
When the series first began, Steve considered himself the height of coolness, but as time progressed, Steve has come to accept that he is indeed a geek, who is at times driven primarily by selfish desires. For the most part he's comfortable with this, save for the points when his father is involved and openly sneers at Steve's hobbies and geeky friends.
Despite low self-esteem and being a geek, Steve has proven to be very knowledgeable and even charismatic, when the need arise. He the primary leader of his group of friends, and is often the one responsible for planning their adventures.
He is also known to have extreme anger issues; and will often destroy things around him when he is angry. In "Family Affair", he destroys several household objects including his grandmother's chandelier when he feels betrayed by Roger.
Steve is also highly sensitive emotionally and frequently cries when he is upset, especially if his actions result in his dad expressing disappointment or disapproval. For example, in "Every Which Way But Lose", he cries when Stan cuts him from the football team. In "Home Adrone", Stan berates Steve for damaging an expensive military drone, leaving the latter in tears. In "The Unbrave One", Roger helps Steve become a hero to gain Stan's approval, but Steve breaks down and cries when Roger steals the credit.
In "Hurricane!", it appeared that Steve might have a fetish for Asians and pregnant women, either separately or even both, when Francine found multiple magazines in Steve's bedroom.
Wheels and the Legman
"Wheels and the Legman" are the recurring alter-egos of Steve and Roger respectively. They are a crime-solving duo created by the two while watching Tex and Mex, about a crime-solving duo with conflicting personalities but work well together. However, upon the creation of the characters, initially, both Roger and Steve wanted to be "Wheels". They settle on Steve when he notes something suspicious about Roger's "angel" partner. They later re-team to search for Hayley's iPod. In "100 A.D.", Klaus notes that every single "mystery" follows this formula:
1. They see a mystery to solve 2. They bicker and argue for the entire episode 3. The culprit always turns out to be Roger
At that point, the two become stuck for a plotline, until they here about Hayley and Jeff Fischer eloping and Stan giving away $50,000 to whoever can find them.
Roger pins the full name of "Squirt "Wheels" Cinnabon" on Steve in "Wheels & the Legman and the Case of Grandpa's Key", a reference to elements of the plot of The Usual Suspects being strung together by objects within sight of the narrator, in this case, a bottle of Squirt soda and a Cinnabon box.
- Appearances of Wheels and the Legman
Klaus and Jeff parody "Wheels and the Legman" as "Fish and the Jeffman" in "Hayley Smith, Seal Team Six" until they are sued for copyright infringement by Roger.
Hobbies and talents
In regards to his geeky-leanings, Steve is into playing Dungeons and Dragons and online gaming. He can read Elvish, has an in-depth knowledge of assorted fantasy and Sci-fi genres. Steve also has an odd love of the macabre, and understands the process of a body decomposing in the earth.
As a result of Stan's teachings, Steve also has a surprisingly impressive numbers of CIA spy skills. He is a master of disguise, educated in using Morse code and can even speak to dolphins. Steve understands gun maintenance and may very well be trained in weapons use. Steve is also occasionally shown to demonstrate detective level skills of analysis and observation.
- In the test pilot, Steve had a longer neck and had round glasses rather than the rectangles on the modern Steve. 
- Despite his awkward geekiness Steve does seem to be unconsciously able to attract pretty girls who are willing to take his virginity such as in "The Vacation Goo". However something always prevents the action from happening. In this example, Becky Arangino is killed in a rockslide.
- Steve has twice been aroused by his sister. Once in "Stannie Get Your Gun" when Roger tricked Steve into believing he was adopted. One of the conclusions Steve reached was that since they weren't related Hayley was ok to kiss in a passionate way. The second time was aroused by a nude portrait for which Hayley was the model in "Meter Made". In the painting her face was hidden so Steve didn't know it was her, at first, so he went into the bathroom and masturbated to his sisters painting. Interestingly, both times Roger was indirectly the reason for these events.
- In "Black Mystery Month" when Steve is in the museum and sees the blood-scrawled message on the ground saying "In the Elf Condom" he was immediately able to figure it out as an anagram for "Find the Monocle." He exclaims that his selective dyslexia disorder paid off.
- Steve has shown to have a bad relationship with cats, first seen in "Choosy Wives Choose Smith", second with his clone in "Son of Stan".
- Steve and his three friends have apparently known each other since toddlerhood as shown in "A Piñata Named Desire".
- He is the only member of the family to have never smoked marijuana.
- It's mentioned that Steve is a fan of Battlestar Galactica in numerous episodes, including "Moon Over Isla Island". However, he sells his friends fake tickets to Battlestar Galactica on Ice in "When a Stan Loves a Woman" to support his Cougar Boost habit.
- It's possible that Steve is bisexual. In "License to Till", Steve and Snot kissed at the end. In "A Ward Show", Snot whispered to him regarding their kiss oath meaning nothing and in "Virtual In-Stanity" Steve mistakes Phyllis' comment regarding Chelsea that a curly haired person wanted to dance for Snot. Steve was also visibly romanced in "Dr. Klaustus" when Roger, as his alter-ego Sgt. Pepper, grabbed and kissed him. In "American Stepdad", Steve and Snot find themselves holding hands. When confronted by Stan in "Why Can't We Be Friends?", Steve denies their being gay with a limp-wrist, but he later reminisces over a strip of photobooth pictures that includes them kissing although Snot's hand keeps their lips from touching. He has a fantasy of girls during a hot tub party in "Blonde Ambition" which includes an image of Snot in a bikini who notes that later they need to have a serious discussion.
- The commentary track for "Red October Sky" reveals that Scott Grimes is rarely able to attend table readings; as such, producer Erik Durbin fills in as him. For the first 4 1/2 seasons, Steve Hely was the temporary voice for Steve.
- It was revealed in "Season's Beatings" that Steve suffers from severe nightmares which are slowly driving him insane.
- Steve has a dislike towards the actor Hugh Grant, as displayed in "The Unbrave One" and "Killer Vacation".
- Scott Grimes once got a hernia from recording the Steve voice too much and that the inspiration for Steve's voice is a mixture of SpongeBob SquarePants and Steve Urkel.