Phyllis Ada Diller (née Driver; July 17, 1917 – August 20, 2012) was an American stand-up comedian, actress, author, musician and visual artist, best known for her eccentric stage persona, self-deprecating humor, wild hair and clothes, and exaggerated, cackling laugh.

Diller was one of the first female comics to become a household name in the United States, credited as an influence by Joan Rivers, Roseanne Barr and Ellen DeGeneres, among others. She had a large gay following. She was also one of the first celebrities to openly champion plastic surgery, for which she was recognized by the cosmetic surgery industry.

Diller contributed to more than 40 films, beginning with Splendor in the Grass (1961). She appeared in many television series, featuring in numerous cameos as well as her own short-lived sitcom and variety show. Some of her credits include Night Gallery, The Muppet Show, CHiPs, The Love Boat, Cybill and Boston Legal, plus 11 seasons of The Bold and the Beautiful. Her voice-acting roles included the monster's wife in Mad Monster Party?, the Queen in A Bug's Life, Granny Neutron in The Adventures of Jimmy Neutron: Boy Genius, and Thelma Griffin in Family Guy.

Diller was born Phyllis Ada Driver in Lima, Ohio on July 17, 1917, the only child of Perry Marcus Driver, an insurance agent, and Frances Ada (née Romshe). She had German and Irish ancestry (the surname "Driver" had been changed from "Treiber" several generations earlier). She was raised Methodist but was a lifelong atheist, even in childhood. Her father and mother were older than most when she was born (55 and 36, respectively) and Diller attended several funerals while growing up. The exposure to death at a young age led her to an early appreciation for life and she later realized that her comedy was a form of therapy.

Diller attended Lima's Central High School, discovering early on she had comic gifts. Later, Diller observed, "I was always a pro— even as a little tiny kid. I was an absolutely perfect, quiet, dedicated student in class. But outside of class, I got my laughs." Diller studied piano for three years at the Sherwood Music Conservatory of Columbia College Chicago, but decided against a career in music after hearing her teachers and mentors play with much more skill than she thought that she would be able to achieve, and transferred to Bluffton College where she studied literature, history, psychology and philosophy.

In 1939, she met Sherwood Diller, the brother of a classmate at Bluffton, and they eloped, marrying in Bluffton on November 4, 1939. Diller did not finish college and was primarily a homemaker, taking care of their five children (a sixth child died in infancy).

During World War II, Sherwood worked at the Willow Run B-24 Bomber Plant, in Ypsilanti Charter Township, Michigan. In 1945, Sherwood Diller was transferred to Naval Air Station Alameda Alameda, California, where he was an inspector.

Diller began working as the women's editor at a small newspaper, and as an advertising copywriter for an Oakland department store.