S. Epatha Merkerson (born Sharon Epatha Merkerson on November 28, 1952) is a Tony Award-nominated and Golden Globe-, Screen Actors Guild- and Emmy Award-winning American actress. She is known for her roles as Reba the Mail Lady on Pee Wee's Playhouse in the 1980s, and as the no-nonsense supervisor, Lt. Anita Van Buren (1993-present) on the long-running television crime drama Law & Order. At present she has been on the show longer than any other cast member. As of the 366th episode in the 16th season, she is the first actress to appear in 300 episodes.

A native of Michigan, S. Epatha Merkerson earned a Bachelor of Fine Arts Degree from Wayne State University. In 1978, she moved to New York City to apply her craft on stage. Although best known since 1993 as the smart and shrewd Lieutenant Anita Van Buren on the long-running TV crime drama "Law & Order" (1990), she has a long list of Broadway and off-Broadway credits and honors that include Drama Desk Award and Tony Award nominations for Best Actress for her performance in the August Wilson play Piano Lesson, The (1995) (TV), a 1992 Obie Award for her performance in "I'm Not Stupid," and a 1998 Helen Hayes Award for her starring role in the Studio Theater production in Washington, DC, of the John Henry Redwood play "The Old Settler." Her first appearance on television was a guest-starring role on an episode of "Cosby Show, The" (1984). Her earliest regular role in television, however, was that of Reba the Mail Woman on "Pee-wee's Playhouse" (1986). Merkerson remains a theatrical force on the stage and on the screen and has the distinction of having been nominated for an Image Award in the Outstanding-Lead-Actress-in-a-Drama category for "Law & Order" (1990) for three consecutive years by the NAACP.