''One on One'' is an American sitcom that aired on Creator/{{UPN}} from 2001 to 2006. It follows sportscaster and ladies' man Flex Washington who, at age 16, had a daughter with his ex-wife Nicole Barnes named Breanna. One day, Breanna, now a teenager, decides to live with him in Baltimore in order to avoid moving to Nova Scotia with her mother. The two soon form an even stronger bond as she enters and explores the pitfalls of high school.

Also along for the ride are Duane Odell Knox, Flex's goofy, short, comedic sidekick and used car salesman, Arnaz Ballard, Breanna's close friend and later boyfriend, and Spirit Jones, her fiery best friend.

Around Season 5, however, [[ExecutiveMeddling the format of the show changed.]] Flex was reduced to a recurring character, and Breanna and Arnaz moved to Los Angeles, and into a house with 4 roommates: Lisa, a dumb yet sweet Filipino, Sarah, a white wannabe [[GoldDigger golddigger]], Cash, a nerdy wannabe paparazzi, and D-Mack, a fake gangsta rapper. They also put a ''ton'' of weird transitions in. It didn't last.
!! The show provides examples of:
* AmicablyDivorced: Flex and Breanna's mother, Nicole, for the most part.
* ArtifactTitle: The title is a reference to Flex and Breanna's new father-daughter relationship. By the end of the 5th season, Flex is written out entirely.
* BetaCouple: Duane and Candy.
* TheCasanova: Flex, especially in Season 1.
* ChuckCunninghamSyndrome: Flex stops appearing by mid-season in Season 5, as does Breanna and Arnaz's landlord Manny. Spirit and Duane disappeared as well.
** Duane was chucked from ''One on One''`s entire ''universe''. When the setting moved to Los Angeles, Duane was left in Baltimore and could have easily appeared on the concurrent season of ''Cuts'', but his relationship with Candy was immediately broken up and he was never seen or mentioned afterwards.
* DawsonCasting: Robert Ri'chard was 18 year old when he was cast as the 15 year old Arnaz. Averted with {{Kyla Pratt}} and Sicily who were about the same age as their characters.
* {{Expy}}: D-Mack is this of D-Money, a character from another UPN show, ''Series/{{Moesha}}'', that was also played by Ray J. They are both wannabe gangsters and troublemakers with families that are actually well off and an older sister played by Brandy.
* MrFanservice: Flex, paticularly in the early seasons. Arnaz would become this in the later seasons.
* MsFanservice: Breanna, especially in the later seasons. Flex's many girlfriends as well.
* FiveTokenBand: Season 5 invoked this intentionally to appeal to wider demographics. It didn't work.
* GenreShift: From a sitcom about a playboy and his teenage daughter to a [[SliceOfLife slice of life]] comedy in Season 5.
* HugeGuyTinyGirl: Flex and Breanna.
* LadyKillerInLove: Flex a couple of times, but particularly with Natalie and later Danielle.
* LeftHanging: The show ends with [[spoiler: Breanna and D-Mack in bed together.]]
* LoveDodecahedron: Arnaz liked Breanna but she only liked him as a friend, then he started dating Ginger. After a while, Breanna starts dating Josh. Arnaz breaks it off with Ginger, then starts having feelings for Breanna again, so Breanna is forced to choose and chooses Arnaz. But then Ginger teams up with Josh to break them up by claming to have slept with Arnaz, while Josh appears shirtless in Breanna's apartment as an OperationJealousy ploy. Then Breanna decides that she and Arnaz are BetterAsFriends so they don't end up like Breanna's parents, but then they get back together later. Then Breanna is jealous of the attractive new singer in Arnaz's band. Then when they get to Los Angeles, they break up mid-season and start dating other people, only for Breanna's new boyfriend to break up with her when he realizes she's still in love with Arnaz. Breanna ends up sleeping with D-Mack. And then the series ends.
* LovableAlphaBitch: Breanna.
* MoralityPet: Breanna becomes this to Flex as she really forces him to evaluate how he treats women, especially as she becomes a woman herself.
* OverprotectiveDad: Flex can be this at times as he worries Breanna will end up becoming pregnant at a young age like her mother did. It's later revealed that much of his over protectiveness is out of fear that Breanna will allow men to treat her the same way that ''he'' treats women.
* PoorlyDisguisedPilot: The Season 3 episode "Splitting Hairs" reduced Flex to a bookending cameo and left out all the others to focus on his brother Kevin and the barbershop he ran, and Tiffany, the daughter of the owner of the shop who wanted it to become a hair salon. In the end, they teamed up and called it "Pharenity" - a mashup of "Phatheadz" (the name of the barbershop) and "Serenity" (the name of Tiffany's prospective hair salon). Unlike most examples, this actually became a series - the UPN sitcom ''Cuts''.
* {{Retcon}}: The conflict of Season 4's finale revolves around Breanna wanting to go to college in California, leaving everyone and everything behind. Arnaz stops her at the last possible moment and confesses that he can't live without her, and they decide to live together in Baltimore after all. Season 5 begins with them moving into a flat in Los Angeles, preparing for California college life.
* ReTool: Season 5 feels like an an entirely new show.
* SassyBlackWoman: Tanya, Flex's first recurring girlfriend, played by Tamala Jones. In later seasons, both Breanna and Spirit become this.
* ShorterMeansSmarter: Averted with Duane and Flex.
* SpinOff: ''Cuts''.
* ThreeAmigos: Breanna, Spirit, and Arnaz.
* ThrowTheDogABone: Duane finally gets a permanent girlfriend in Candy during Season 3. Also both Lisa and Benjaman (the snarky owner of the coffee shop that Breanna and friends frequent in Season 5) get together in the Season 5 finale. Lisa had spent most of the season pining after D-Mack who either ignored her or treated her like garbage while Benjamin pined for her.
* TinyGuyHugeGirl: Duane and Candy.
* WillTheyOrWontThey: Breanna and Arnaz for the ''entire'' series.
-->'''Spirit:''' [[FandomNod Y'all get on my nerves]].
* WithAFriendAndAStranger: Spirit and Arnaz were childhood friends. Breanna was the stranger of the trio.