# Flex Alexander
**Flex Alexander** is the stage name of **Marc Alexander Knox** (born 1970), an American actor, comedian, dancer, and producer best known for starring as single father Mark "Flex" Washington on the UPN sitcom *One on One* from 2001 to 2006 and for portraying [Michael Jackson](https://www.edgepedia.org/michael-jackson) in the 2004 VH1 television film *Man in the Mirror: The Michael Jackson Story*.[1](https://www.tvguide.com/celebrities/flex-alexander/bio/3030719741/) • [2](https://www.cbsnews.com/news/flex-alexander-plays-king-of-pop/) He built his career in stages: first as a club dancer and touring choreographer, then as a stand-up comedian, and finally as a screen actor with more than 50 credited television and film roles.[3](https://www.tvguide.com/celebrities/flex-alexander/credits/3030719741/)
| Key fact | Detail |
|---|---|
| Birth name | Marc Alexander Knox, born 1970 in New York City[1](https://www.tvguide.com/celebrities/flex-alexander/bio/3030719741/) |
| Signature role | Mark "Flex" Washington on *One on One* (UPN, 2001–2006), also credited as co-executive producer and story by[3](https://www.tvguide.com/celebrities/flex-alexander/credits/3030719741/) |
| Notable film role | Michael Jackson in *Man in the Mirror: The Michael Jackson Story* (VH1, 2004)[2](https://www.cbsnews.com/news/flex-alexander-plays-king-of-pop/) |
| Dance career | Nightclub dancer in his teens; discovered by DJ Spinderella and toured with Salt-n-Pepa for three years; choreographed for Mary J. Blige and Queen Latifah[4](https://urbanbridgez.com/2020/10/17/ub-revisit-flex-alexander-talks-the-bronx-family-and-one-on-one/) |
| Recognition | Two BET Comedy Award nominations (2004, 2005) and multiple NAACP Image Award nominations for *One on One* and the Jackson biopic[1](https://www.tvguide.com/celebrities/flex-alexander/bio/3030719741/) • [5](https://aalbc.com/interview/Flex-Alexander-The-Soulaughable-Interview) |
| Family | Married R&B singer Shanice on February 19, 2000; two children, Imani (born 2001) and Elijah (born 2004)[6](https://www.imdb.com/name/nm0018416/bio/) |
| Height | 6 ft 3¼ in (1.91 m)[6](https://www.imdb.com/name/nm0018416/bio/) |
## Early life and dance career
Alexander was born in New York City in 1970, the son of Alethia Knox and [Robert Whitehead](https://www.edgepedia.org/robert-whitehead), and grew up in the Bronx.[4](https://urbanbridgez.com/2020/10/17/ub-revisit-flex-alexander-talks-the-bronx-family-and-one-on-one/) He attended Manhattan's High School of Art and Design, where he studied architecture.[1](https://www.tvguide.com/celebrities/flex-alexander/bio/3030719741/) His adolescence was troubled: he has described getting into fights, selling drugs, and carrying a gun, and he left home at 15. He has said that a brush with death in 1988 scared him away from selling drugs.[4](https://urbanbridgez.com/2020/10/17/ub-revisit-flex-alexander-talks-the-bronx-family-and-one-on-one/) • [7](https://www.rottentomatoes.com/celebrity/mark_flex_knox)
**Dancing came first.** His first paying performance was breakdancing at a Bar Mitzvah for $50.[8](https://urbanbridgez.com/2010/06/22/exclusive-actor-flex-alexander-speaks-to-urbanbridgez-com/) As a nightclub dancer in his teens, his acrobatic floor style earned him the nickname "Flex" and caught the attention of DJ Spinderella of Salt-n-Pepa, who recruited him for the group's tour, where he spent three years.[4](https://urbanbridgez.com/2020/10/17/ub-revisit-flex-alexander-talks-the-bronx-family-and-one-on-one/) He went on to choreograph for recording artists including [Mary J. Blige](https://www.edgepedia.org/mary-j-blige), [Queen Latifah](https://www.edgepedia.org/queen-latifah), Toni! Toni! Toné!, and [Heavy D](https://www.edgepedia.org/heavy-d) & the Boys, and served as assistant choreographer on the film *New Jack City*.[4](https://urbanbridgez.com/2020/10/17/ub-revisit-flex-alexander-talks-the-bronx-family-and-one-on-one/) • [8](https://urbanbridgez.com/2010/06/22/exclusive-actor-flex-alexander-speaks-to-urbanbridgez-com/)
## Comedy and early acting
In 1989, encouraged by a friend, [Alexander](https://www.edgepedia.org/alexander) made his stand-up debut at the Uptown Comedy Club in Manhattan, a venue he has described as notoriously challenging.[7](https://www.rottentomatoes.com/celebrity/mark_flex_knox) • [8](https://urbanbridgez.com/2010/06/22/exclusive-actor-flex-alexander-speaks-to-urbanbridgez-com/) He later performed at clubs including Stand Up New York, The Improv, the Laugh Factory, and the Comic Strip, and appeared on *Showtime at the Apollo* and *Def Comedy Jam*.[8](https://urbanbridgez.com/2010/06/22/exclusive-actor-flex-alexander-speaks-to-urbanbridgez-com/)
His screen debut came in 1992, with a small role as a contest auditioner in the crime drama *[Juice](https://www.edgepedia.org/juice-1992-film)*, opposite Queen Latifah and [Tupac Shakur](https://www.edgepedia.org/tupac-shakur), and an appearance on the sketch series *Uptown Comedy Club*.[9](https://www.nndb.com/people/811/000131418/) • [1](https://www.tvguide.com/celebrities/flex-alexander/bio/3030719741/) Through the 1990s he took supporting film roles in *Money Train* (1995), *The Sixth Man* (1997), *City of Industry* (1997), *She's All That* (1999), and *Out Cold* (2001), while building television credits on *Sister, Sister*, *Moesha*, *New York Undercover*, *Brooklyn South*, and *The Parkers*.[9](https://www.nndb.com/people/811/000131418/) He also starred in three short-lived series: *Where I Live* (1993), *Homeboys in Outer Space* (1996–97), and [Steven Bochco](https://www.edgepedia.org/steven-bochco)'s *Total Security* (1997).[4](https://urbanbridgez.com/2020/10/17/ub-revisit-flex-alexander-talks-the-bronx-family-and-one-on-one/) • [10](https://www.tvmaze.com/people/17291/flex-alexander)
## One on One
*One on One*, which premiered on UPN in September 2001, made Alexander a household name. He played Flex Washington, a bachelor sportscaster whose life changes when his teenage daughter Breanna, played by [Kyla Pratt](https://www.edgepedia.org/kyla-pratt), comes to live with him.[11](https://dabltvnetwork.com/stories/one-on-one-turns-25-heres-how-flex-alexander-said-he-came-up-with-the-idea-for-the-show) The series ran five seasons, from 2001 to 2006.[5](https://aalbc.com/interview/Flex-Alexander-The-Soulaughable-Interview) Alexander was also credited as co-executive producer and for the story, and he later said he originated the show's core idea, a single young father raising his daughter, years before it was produced, though Eunetta T. Boone is credited as the creator.[3](https://www.tvguide.com/celebrities/flex-alexander/credits/3030719741/) • [11](https://dabltvnetwork.com/stories/one-on-one-turns-25-heres-how-flex-alexander-said-he-came-up-with-the-idea-for-the-show)
The role brought him his main award recognition: nominations for the NAACP Image Award for Outstanding Actor in a Comedy Series in 2003, 2004, and 2005, and BET Comedy Award nominations for Outstanding Lead Actor in a Comedy Series in 2004 and 2005.[1](https://www.tvguide.com/celebrities/flex-alexander/bio/3030719741/)
## Man in the Mirror
In 2004, while starring on *One on One*, Alexander took the title role in VH1's biographical television film *Man in the Mirror: The Michael Jackson Story*, covering Jackson's life from the *Thriller* era onward. The film was produced while Jackson was facing child-molestation charges, and Alexander said he wanted it to take an objective view and let audiences decide for themselves.[2](https://www.cbsnews.com/news/flex-alexander-plays-king-of-pop/)
He had one month to prepare. He said the hardest part was sustaining Jackson's speaking voice between shooting days; the dancing came easily given his professional background, and he declined prosthetic makeup, with sessions instead running about three hours.[2](https://www.cbsnews.com/news/flex-alexander-plays-king-of-pop/) The performance earned him an NAACP Image Award nomination for Outstanding Actor in a Television Movie, Mini-Series or Dramatic Special in 2005.[1](https://www.tvguide.com/celebrities/flex-alexander/bio/3030719741/)
## Later career
After *One on One* ended, Alexander worked steadily in both drama and comedy. His film work included *Snakes on a Plane* (2006), as Three G's; *[The Hills Have Eyes 2](https://www.edgepedia.org/the-hills-have-eyes-2)* (2007); Clement Virgo's boxing drama *Poor Boy's Game* (2007), opposite [Danny Glover](https://www.edgepedia.org/danny-glover); and *Love... & Other 4 Letter Words* (2007).[9](https://www.nndb.com/people/811/000131418/) • [12](https://watch.plex.tv/en-GB/person/flex-alexander) On television he appeared as Evan Forrester on *Grey's Anatomy* and its spin-off *Station 19*, played Walter on Showtime's *Masters of Sex*, and took guest roles on *Blue Bloods*, *CSI: Miami*, *Lucifer*, *Kenan*, and *mixed-ish*, and a recurring part as Low Jack on *Carl Weber's The Family Business*.[10](https://www.tvmaze.com/people/17291/flex-alexander)
He also moved behind the camera, serving as executive producer of the series *Lawd Have Mercy* (2017), in which he also starred as co-host.[3](https://www.tvguide.com/celebrities/flex-alexander/credits/3030719741/) With his wife he starred in the OWN reality series *Flex & Shanice* (2014).[10](https://www.tvmaze.com/people/17291/flex-alexander) In the 2020s he returned to stand-up comedy and touring, and in 2026 he appeared as Erik Troy in the thriller *Unrequited*.[13](https://www.fox5dc.com/video/1744869) • [12](https://watch.plex.tv/en-GB/person/flex-alexander)
## Personal life
Alexander married the R&B singer [Shanice](https://www.edgepedia.org/shanice) (Shanice Wilson) on February 19, 2000. They have two children: daughter Imani, born in 2001, and son Elijah, born in 2004.[6](https://www.imdb.com/name/nm0018416/bio/) He is a member of Phi Beta Sigma Fraternity, Inc.[6](https://www.imdb.com/name/nm0018416/bio/) In interviews he has credited prayer and family with sustaining him through a difficult youth and a long career, and has described his grandmother, Christola Williams, as his hero.[5](https://aalbc.com/interview/Flex-Alexander-The-Soulaughable-Interview)
## References
1. [Flex Alexander Biography, TV Guide](https://www.tvguide.com/celebrities/flex-alexander/bio/3030719741/)
2. [Flex Alexander Plays King Of Pop, CBS News (August 6, 2004)](https://www.cbsnews.com/news/flex-alexander-plays-king-of-pop/)
3. [Flex Alexander List of Movies and TV Shows, TV Guide](https://www.tvguide.com/celebrities/flex-alexander/credits/3030719741/)
4. [UB ReVisit: Flex Alexander Talks The Bronx, Family and One on One, UrbanBridgez (October 17, 2020)](https://urbanbridgez.com/2020/10/17/ub-revisit-flex-alexander-talks-the-bronx-family-and-one-on-one/)
5. [Flex Alexander - The "Soulaughable" Interview, AALBC](https://aalbc.com/interview/Flex-Alexander-The-Soulaughable-Interview)
6. [Flex Alexander - Biography, IMDb](https://www.imdb.com/name/nm0018416/bio/)
7. [Flex Alexander Movies & TV Shows List, Rotten Tomatoes](https://www.rottentomatoes.com/celebrity/mark_flex_knox)
8. [Exclusive: Actor Flex Alexander Speaks to UrbanBridgez.com (June 22, 2010)](https://urbanbridgez.com/2010/06/22/exclusive-actor-flex-alexander-speaks-to-urbanbridgez-com/)
9. [Flex Alexander, NNDB](https://www.nndb.com/people/811/000131418/)
10. [Flex Alexander, TVmaze](https://www.tvmaze.com/people/17291/flex-alexander)
11. ['One on One' turns 25! Here's how Flex Alexander said he came up with the original core idea for the show, Dabl](https://dabltvnetwork.com/stories/one-on-one-turns-25-heres-how-flex-alexander-said-he-came-up-with-the-idea-for-the-show)
12. [Flex Alexander Movies and TV Shows, Plex](https://watch.plex.tv/en-GB/person/flex-alexander)
13. [Flex Alexander on returning to comedy, TV career, FOX 5 DC (November 21, 2025)](https://www.fox5dc.com/video/1744869)
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*Topic: Encyclopedia › Arts and culture › Screen and stage › Film and television › Films and standalone screen works › Film people and crafts › Film actors and performers › Actors and actresses by country or nationality › American actors and actresses › Surnames A to F*
*Initially written Sep 17, 2026 · Reviewed: Sep 17, 2026; Oct 25, 2026 · Edited: Oct 12, 2026; Oct 25, 2026 · Last review: Oct 25, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license