Furth was born George Schweinfurth in Chicago, Illinois, the son of Evelyn (née Tuerk) and George Schweinfurth. He received a Bachelor of Science in Speech at Northwestern University in 1954 and received his master’s degree from Columbia University.  A life member of the Actors Studio, Furth made his Broadway debut as an actor in the 1961 play A Cook for Mr. General, followed by the musical Hot Spot two years later. He was also known for his collaborations with Stephen Sondheim: the highly successful Company, the ill-fated Merrily We Roll Along and the equally ill-fated drama, Getting Away with Murder. Furth penned the plays Twigs, The Supporting Cast and Precious Sons, and wrote the book for the Kander and Ebb musical, The Act.  One of Furth’s last writing projects was a foray into an area where he had not previously endeavored. Furth penned the lyrics for a musical revue, with music by Doug Katsaros. Furth and Katsaros shaped the work with San Francisco director Mike Ward into “The End-a new musical revue”. The piece was performed at San Francisco’s New Conservatory Theatre Center during the summer of 2004 and was billed as a “Pre-U.S. Tour Workshop Production”. The piece was reworked twice, with the title changing to Last Call and Happy Hour, respectively.

Frequently cast as a bespectacled, ineffectual milquetoast, Furth appeared in such films as The Best Man, Myra Breckinridge, Hooper, Blazing Saddles, Oh God!, Shampoo, The Cannonball Run, Young Doctors in Love, Doctor Detroit, Bulworth and Butch Cassidy and the Sundance Kid. His many television credits include Tammy, McHale’s Navy, Ironside, I Dream of Jeannie, That Girl, Green Acres, The Monkees, Batman, The Odd Couple, Bonanza, Happy Days, All in the Family, Murphy Brown, L.A. Law, Dr. Quinn, Medicine Woman, Murder, She Wrote, Little House on the Prairie, Love, American Style, Adam-12, F Troop and the made-for-TV film The Scarlett O’Hara War, in which he portrayed famed film director George Cukor. He was a regular in the cast of the short-lived 1976 situation comedy The Dumplings.  He adapted his play Twigs as a 1975 television production, starring Carol Burnett. He also worked as a voice actor in several episodes of the animated television series The Adventures of Don Coyote and Sancho Panda for Hanna-Barbera Productions. Never married, Furth died on August 11, 2008 at the age of 75. The exact cause of death is unknown, although he had been hospitalized for a lung disease at the time.