Blye was born Margaret Jane Blye in Houston, Texas. Her sister was casting director Judy Blye Wilson. After studying business at the University of Texas, she went to UCLA, where she became involved in acting. Her performance in a production of West Side Story there was seen by a talent scout for 20th Century Fox studios.
Blye was a regular on the ABC-TV program Kodiak in the role of police radio dispatcher Maggie.
She appeared in a number of popular television series. Among her first roles was that of defendant Betty Kaster in the 1965 Perry Mason episode, "The Case of the Lover's Gamble." She also appeared on Hazel, Gunsmoke and Ben Casey early in her career.
Her later television roles included Hart to Hart, The Rockford Files, and Lois & Clark: The New Adventures of Superman. She appeared in four episodes of the series In the Heat of the Night, including the pilot episode.
A 1983 article about Blye, distributed by the Newspaper Enterprise Association, contained the comment: "Maggie Blye was supposed to be the next big movie star. She ended up making a string of films that were supposed to be blockbusters but didn't even bust a balloon, much less a block."
She appeared in the 1967 Paul Newman film Hombre and the 1969 version of The Italian Job as Michael Caine's girlfriend, as well as Waterhole No. 3 (1967) starring James Coburn. Blye appeared with Coburn again in the 1975 film Hard Times. Her other movie roles included The Sporting Club (1971), Walking Tall: Final Chapter (1977), the third film about the life of Sheriff Buford Pusser, and the horror film, The Entity (1982).
Blye's career took a turn in the late 1970s. Her obituary in the online version of The Telegraph pointed out: "By the end of the decade, however, Maggie Blye was no longer being considered for romantic roles. 'In the space of two years,' she noted, 'I went from playing daughters to mothers.'”
Blye appeared in several films in the 2000s, including 2004's Last Goodbye and the 2005 horror comedy The Gingerdead Man.
Blye died on March 24, 2016 from cancer at her home in West Hollywood, California, aged 73. She was survived by one brother, Richard Blye, and one sister, Judy Blye Wilson.Summer and Smoke (1961) as Dusty (uncredited)
Hombre (1967) as Doris
Waterhole No. 3 (1967) as Billee Copperud
Diamonds for Breakfast (1968) as Honey
The Italian Job (1969) as Lorna
The Sporting Club (1971) as Janey
Every Little Crook and Nanny (1972) as Stella Ganucci
Ash Wednesday (1973) as Kate Sawyer
Hard Times (1975) as Gayleen Schoonover
Mayday at 40,000 Feet! (1976) as Susan Mackenzie
Walking Tall: Final Chapter (1977) as Luan Paxton
Little Darlings (1980) as Ms. Bright
Liar's Moon (1982) as Ellen 'Babs' Duncan
The Entity (1982) as Cindy Nash
Kidco (1984) as Joan Cessna
Mischief (1985) as Claire Miller
Soft Toilet Seats (1999)
The Gingerdead Man (2005)