Tom Sizemore rose in prominence throughout the 1990s, establishing himself as a memorable tough guy character, sought after by the most respected directors in the business. Born in Detroit on 29 November, 1961, Sizemore grew up idolizing the tough guy characters of the movies he watched. After attending Wayne State University, he got his master's degree in theater from Temple University in 1986.

Like many he moved to New York City and struggled, waiting tables and performing in plays. His first break came when Oliver Stone cast him in a bit part in Born on the Fourth of July. Bigger roles soon followed throughout the early 1990s, such as Guilty by Suspicion, True Romance, and Striking Distance. 1994 proved to be an even bigger year for Sizemore, as he won the role of "Bat Masterson" in Kevin Costner's star-studded biopic Wyatt Earp, as well as one of his first truly memorable roles as "Detective Jack Scagnetti" in Oliver Stone's controversial Natural Born Killers. In 1995 he appeared in Devil in a Blue Dress, Strange Days, as well as the acclaimed crime epic Heat, directed by Michael Mann. Sizemore's first big leading role is in The Relic, the big budget effects thriller directed by Peter Hyams.

According to a 2001 interview in The Calgary Sun, Sizemore entered a drug rehab program in 1998 after his mother and his friend Robert De Niro appeared on his doorstep during the filming of Witness to the Mob. Telling him they were there to drive him to jail or to rehab, Sizemore chose rehab. After he completed rehab, he counseled teens involved in substance abuse.

Offered both a role in WWII films directed by both Terrence Malick and Steven Spielberg, Sizemore chose the role of "Sergeant Horvath" in Saving Private Ryan. The role and film received widespread acclaim and introduced Sizemore's talents to a much broader audience in a more human and well-rounded role than he had previously been given. Sizemore also credits this shoot and Steven Spielberg for helping him with his recovery from addiction, with Steven Spielberg threatening to re-shoot the entire film if Sizemore failed a drug test even once.

After a flamboyant and uncredited mobster role in Enemy of the State, Sizemore then portrayed a psychotic paramedic in Bringing Out the Dead directed by Martin Scorsese. Seemingly taking it easy, he then turned in fine but stereotypical performances in Play It to the Bone, Red Planet, and Pearl Harbor. Sizemore then received another leading role in the high-profile military drama Black Hawk Down directed by yet another legendary director, Ridley Scott.

Specializing in the sort of ultimate tough guy/manly man roles that hearken back to a different era in film, Sizemore continues to be a favourite of Hollywood's greatest directors. Never afraid to speak his mind about anyone and anything, his sense of blunt honesty and lack of pretentiousness is refreshing. A commanding voice and presence on film, Sizemore looks to continue as one of Hollywood's greatest actors.
Arrested in Los Angeles, after his wife called police claiming she'd been physically injured by Tom during an argument at their apartment. [24 January 1997] According to a 2001 interview with The Calgary Sun, he credits Robert De Niro with turning his life around during the filming of Witness to the Mob. De Niro showed up on his doorstep with Tom's mother and told him they were there to drive him to jail or rehab. He chose rehab. Formerly engaged to Heidi Fleiss. His brother, Aaron, is a writer and lives in Detroit. His younger brother is Paul Sizemore Is an Italian-American. Enjoys weightlifting. Practiced martial arts as a teenager. Attended Wayne State University in Detroit, Michigan. Had his nose accidentally broken by Juliette Lewis during the filming of the prison cell fight scene in Oliver Stone's _Natural Born Killers (1994)_ . Has played characters in seven movies who have died in shootouts: True Romance, Enemy of the State, Saving Private Ryan, Heat, Natural Born Killers, Devil in a Blue Dress and Dreamcatcher. If counting voice work, the number goes up to eight!: He did the voice of Sonny Forelli in Grand Theft Auto: Vice City, who is killed in a gang shootout. As a struggling young actor in New York, Sizemore worked for three years as a waiter in the World Trade Center. Auditioned six times for the part of Mr. Pink in Reservoir Dogs. Gained 44 lbs. to portray John Gotti in Witness to the Mob by gorging on ice cream, pizza, pasta with cream sauce, meatball sandwiches and drinking weight gainer shakes. In February 2005, he failed a court-ordered drug test after he was caught trying to use a prosthetic penis to fake the results, the second time he has been caught trying this. Was in attendance at Chris Penn's funeral Has twin sons Jayden and Jagger born in July of 2005 with ex-girlfriend Janelle McIntire. Claims to have spent $11 million on lawyers and legal fees fighting previous drug and domestic violence charges.