Born in Memphis, TN, Williams lived on a farm with his maternal grandparents until he was 9 years old in nearby Millington. Williams then moved to Chicago with his mother where he graduated from Wendell Phillips High School and enrolled in the General Motors Institute, the automaker's engineering school. Soon after, he was drafted into the Army. He served in the 2nd Armored Division, stationed in Gilhausen, Germany and became Divisional Champion with the United States Army Boxing Team, Middleweight Division.
Upon Honorable Discharge, Williams worked for the Post Office as a mailman. After delivering the mail in sub zero temperatures, he went to work in Chicago's garment district as an apparel salesman. His good looks, high energy and effective salesmanship caught the attention of advertising executives who encouraged him to pursue a career in modeling, which he did with great success for several years.
Long fascinated by the local theater scene, Williams began to investigate his own acting abilities. He worked steadily in Chicago theater with dynamic performances in such productions as Taming of the Shrew, Purlie, The Mighty Gents, All Honorable Men, Warp, Ceremonies in Dark Old Men, Black Picture Show, Don Juan, Slow Dance on the Killing Ground and Medal of Honor Rag (Milwaukee Rep.). He was twice nominated for the prestigious Joseph Jefferson Award for his performances in Joplin and Cinderella Brown. His love for the theatre continued as he portrayed the patriarch of the family in The Letter at The Hudson Theatre, L.A. receiving critical acclaim.
Complementing his stage credits were a number of roles in feature films shot in Chicago such as Cooley High, Doctor Detroit and the now classic The Blues Brothers. Williams got his first taste of Los Angeles, in 1980, while doing P.R. for a Movie of the Week - Dummy in which he co-starred with LeVar Burton and Paul Sorvino. In 1982 he moved to L.A. permanently. Among his motion picture credits are Corrina, Corrina, Jason Goes to Hell: The Final Friday, Twilight Zone: The Movie, Missing in Action II: The Beginning, The Sender, Firetrap, Route 666 and Elite.
On television Williams became internationally recognized for his starring role as the, tough yet compassionate, police captain on 21 Jump Street. The series was praised by youth organizations worldwide for its realistic and sensitive portrayal of topical teen issues. One hundred and two episodes of 21 Jump Street were produced, the last episode, Williams directed. His other television credits include a co-starring role on The Equalizer and starring in the title role in Disney Presents 100 Lives of Black Jack Savage on NBC. The series allowed Williams to showcase his diverse talents as both a dramatic and comedic actor. As the recurring character X on FOX's macabre, hit series, The X-Files, Williams played X with a powerful, deadly, ambiguous quality. He also appeared in the television movies Revolver, Heroes of the Storm, The Marva Collins Story, Dummy, Dreams of Gold: The Mel Fisher Story, The Lost Honor of Kathryn Beck, Touchdown, Silent Witness, Deep Red and Legacy of Sin: The William Coit Story.
His long list of guest starring roles on episodic television include playing the President of the United States on Seaquest, a homeless person on the "Greeter" episode of Stingray, and a multitude of diverse characters on The Hughley's, Total Recall, Suddenly Susan, Any Day Now, L.A. Law, Dukes of Hazzard, Wiseguy, Hill Street Blues, The A-Team, Hunter, Gimme A Break, Martin, Models Inc., Sister, Sister, NYPD Blue with recurring roles on Stargate SG-1 and City of Angels.
Williams portrays L.A.P.D. Detective August Brooks in the series LA Heat, which airs daily on TNT. Williams plays Brooks as a man with great inner strength, compassion and a sense of humor. When off-duty, Brooks runs a boxing gym for underprivileged youth, allowing Williams to display his boxing abilities.
On Showtime's original series, Linc's, Williams plays the title role of Russell "Linc" Lincoln. Linc is the politically conservative proprietor of the Washington DC bar and grill who caters to a diverse crowd.
When he is not in front of the camera, Williams is an active supporter of a variety of youth-oriented causes and organizations. Drawing on his own experience of being wounded by a handgun at 19 and being robbed at gunpoint at 26, Williams has become an avid proponent of gun control legislation and is actively involved in a celebrity committee for The Center to Prevent Handgun Violence. He is also dedicated to volunteering his time and energy to the Make-A-Wish Foundation, Alta Bates Hospital, Children's Cancer Center and many other charities.