Born Elizabeth Blythe Slaughter, she began her stage work in such theatrical pieces as So Long Letty and The Peacock Princess.
After touring Europe and the States, she entered films in 1918 at the Vitagraph Studios in Brooklyn, then she was brought to Hollywood's Fox studio as a replacement for actress Theda Bara.
As famous for her revealing costumes as for her dramatic skills, she became a star in such exotic films as The Queen of Sheba (1921), Chu-Chin-Chow (made in 1923; released by MGM in the US 1925) and She (1925).
She was also seen to good advantage in less revealing films like Nomads of the North (1920) with Lon Chaney and In Hollywood with Potash and Perlmutter (1924), produced by Samuel Goldwyn.
Other roles were as an opera star, unbilled in Garbo's The Mysterious Lady. She continued to work as a character actress. One of her last roles was a small uncredited role in a crowd scene in 1964's My Fair Lady.
She is famous for being one of the first actresses to appear on film in the nude, or nearly so, during The Roaring Twenties.
She is reported to have said, "A director is the only man besides your husband who can tell you how much of your clothes to take off."
Blythe was married to the movie director Paul Scardon from 1919 until his death in 1954.
Betty Blythe died of a heart attack in Woodland Hills, California in 1972, aged 78. She is buried at Forest Lawn Memorial Park in Glendale, California.