Cynthia Harris, a versatile actress who played Paul Reiser’s assertive mother in the hit 1990s sitcom “Mad About You” and won acclaim in the British TV mini-series “Edward and Mrs. Simpson,” died on Monday at her home in Manhattan. She was 87.

Her death was confirmed by her nephew Dan Harris.

The Emmy- and Golden Globe-winning “Mad About You” aired on NBC from 1992 to 1999 and was revived in 2019 by Spectrum Originals, a streaming site. It starred Paul Reiser and Helen Hunt as newlyweds (in the roles of Paul Buchman, a documentary filmmaker, and Jamie Stemple Buchman, a public relations specialist) who, living in Greenwich Village, must cope with both frivolous and eventful barriers to marital bliss, including Paul’s overbearing mother, Sylvia.

Miss Harris’s Sylvia was a recurring character on “Mad About You” for four seasons and became a regular in 1997, often butting heads with Ms. Hunt’s Jamie but also sharing warmer moments. She reprised the role in the revival. All told, Miss Harris (who preferred that honorific) appeared in 73 episodes of the sitcom.

In “Edward and Mrs. Simpson,” a seven-part dramatization broadcast in Britain in 1978 and in the United States in 1979, Miss Harris played Wallis Simpson, the twice-divorced American for whom King Edward VIII, played by Edward Fox, abdicated the British throne. For her performance she was nominated for best actress by the British Academy of Film and Television Arts.

She made her Broadway debut in 1963, and appeared in dozens of television shows and movies. For 21 years she was also the artistic director and a founding member of the Actors Company Theater, an off-Broadway collaboration founded in 1992 that calls itself “a company of theater artists that reveals, reclaims, and reimagines great plays of literary merit.”

Cynthia Lee Harris was born on Aug. 9, 1934, in Manhattan to Saul and Deborah Harris. Her father was a haberdasher, her mother a homemaker.

After graduating from Monroe High School in the Bronx in 1951, she earned a degree in theater and literature from Smith College in Massachusetts. Afterward she worked as an assistant stage manager.

Miss Harris made her New York City acting debut with an improvisational group called The Premise and then acted for eight years as a resident member of The Open Theater, an avant-garde ensemble. Her first film role was as Mary Desti in “Isadora” (1968), based on the life of Isadora Duncan and starring Vanessa Redgrave. She also had roles in the movies “Reuben, Reuben” (1983) and “Three Men and a Baby” (1987), among others.

Playing Wallis Simpson may have been the closest Miss Harris came to stardom, but she had no shortage of roles on television, in theater and in film.

She appeared on Broadway in the Stephen Sondheim and George Furth musical “Company” in 1971 and in episodes of television shows including “Archie Bunker’s Place,” “All My Children,” “The Bob Newhart Show,” “L.A. Law,” “Three’s Company” and “Sirota’s Court.”

Miss Harris was familiar to radio listeners and TV viewers in the 1970s and ’80s as “Mrs. B” in commercials for the now defunct Bradlees discount department store chain.

She married the theater manager and producer Eugene V. Wolsk in 1961; they divorced in 1972. She is survived by her brother, Dr. Matthew Harris; and her partner, Nathan Silverstein.