Robert Mandan (born February 2, 1932) is an American actor, best known for his role as Chester Tate on the satirical sitcom Soap from 1977-81.

His earlier portrayals in serials were playwright David Allen on the NBC's From These Roots from 1958 to 1961 and businessman Sam Reynolds on Search for Tomorrow from 1965 to 1970. He also appeared on Broadway in the 1970 musical Applause.

His sitcom appearances prior to Soap include an auctioneer in the 1972 premier episode of Sanford and Son, attorney Mr. Morrison in a 1973 episode of All in the Family, and Barry, gay friend of Maude on a 1974 episode of Maude. He also guest-starred in an episode of the western series Sara in 1976.

He played Mr. Kirby in the 1979 NBC television adaptation of You Can't Take it With You and the ineffective but well-meaning Colonel Fielding on the 1981 TV adaptation of Private Benjamin

Roles in two movies in 1982 were Zapped! as Walter J. Coolidge and The Best Little Whorehouse in Texas as Senator Charles Wingwood.

In 1984 he played James Bradford on ABC's Three's a Crowd opposite John Ritter and in 1986 as Peace Corps member Dr. Bruce Gaines, who married Mrs. Garrett (played by Charlotte Rae) in her final episodes on The Facts of Life. He also appeared as Steven in the 1990 episode of The Golden Girls entitled "Great Expectations".

In 1991 he reunited with his former TV wife Katherine Helmond from Soap on Who's the Boss?, in 1993 played Cardassian character Kotan Pa'Dar in Star Trek: Deep Space Nine episode "Cardassians", and in Married... with Children in the episode "The D'Arcy Files" (1994).

His return to serials include the role of Maxwell Hammer, a friend of Minx, in Santa Barbara (1990), Mr. Jonesy alongside Louise Sorel on Days of Our Lives from 1997-98 and guest-starred as a judge on General Hospital in early 2006.