One on One is an American sitcom that aired on UPN from September 3, 2001, to May 15, 2006. The series stars Flex Alexander as a single sportscaster, who becomes a full-time father when his ex-wife decides to accept a job out of the country and his teenage daughter Breanna (Kyla Pratt) moves in with him. The series was set in Baltimore for the first four seasons, before changing settings to Los Angeles for the final season. The series was a joint production of the Greenblatt/Janollari Studio and Daddy's Girl Productions in association with Paramount Network Television.

The series featured guest appearances from numerous celebrities and athletes, including Lil' Zane, Chris Brown, Lil' Romeo, Eve, Lloyd, Floetry, Angie Stone, Mario, Omarion, Brandy, Solange Knowles, Nina Sky, Marques Houston, Smokey Robinson, Kim Fields, Avant, Jennifer Freeman, Nate Dogg, Bobby V, Claudia Jordan, Ruben Studdard, and Lisa Leslie. The show was cancelled months before The WB and UPN merged to form The CW.

The show would also have a spin-off series Cuts, which follows Flex's younger stepbrother Kevin Barnes running the local barbershop/day spa with a spoiled brat named Tiffany Sherwood after her father Jack Sherwood purchased the shop. The show premiered as a mid-season replacement during the 2004–2005 television season. The show lasted for only two seasons and was also canceled when UPN and The WB merged to form The CW.