Cannon was raised in Seattle, the daughter of a Baptist insurance broker and a Jewish homemaker. She began performing at the synagogue she attended with her mother, singing in the choir. By the late 50s, she was acting in TV shows, beginning with a "Playhouse 90" alongside Art Carney and appeared on such series as "Have Gun, Will Travel". Future husband Cary Grant (35 years her senior) first noticed Cannon in a 1961 episode of "Malibu Run". Cannon made her feature film debut in 1960 in "The Rise and Fall of Legs Diamond". She then went to New York and did some theater work. After marrying Grant in 1965 and bearing his only child, Jennifer Grant (now an actress), Cannon retired from the screen. But three years later, the marriage was on the rocks and the pair split in what was reportedly an acrimonious divorce. Cannon headed back to work, appearing in an episode of "Medical Center". She also was tapped by director Paul Mazursky to play the conservative Alice in the wife-swapping comedy "Bob & Carol & Ted & Alice" (1969), for which she was nominated for an Academy Award as Best Supporting Actress. With her career in full swing, she went on to appear as the wife of a network president in "Jacqueline Susann's The Love Machine" (1971) and portrayed a Hollywood agent said to be based on Sue Mengers in "The Last of Sheila" (1973). Another break came with "Heaven Can Wait" (1978), in which she was the murderous wife of the man whose body Warren Beatty decides to inhabit. One of her first scenes was a screen classic--when she sees her presumed dead husband alive and screams. Her hysterical (in both meanings of that word) performance earned her a second Best Supporting Actress Oscar nod. Cannon later starred opposite Willie Nelson in "Honeysuckle Rose" (1980) and again was a hysterical wife, this time married to playwright Michael Caine in "Deathtrap" (1982). That same year, she was a ditsy actress opposite Al Pacino in "Author! Author!". By the mid-80s, however, good feature film roles started to become rare. By 1988, Cannon was lending her sizable talents to the low brow "Caddyshack II", playing a blue blood black sheep who is charmed by Jackie Mason. A reteaming with Mazursky on "The Pickle" (1993) was a box-office flop as were the Disney remake "That Darn Cat" and Tom Schulman's directorial debut "Eight Heads in a Duffel Bag" (both 1997). But 1997 also brought a stellar turn as Elaine Stritch's bikini-clad daughter being romanced by con man Walter Matthau in the middling "Out to Sea".

Cannon moved into TV-movies in 1974, playing Benjamin 'Bugsy' Siegel's moll "Virginia Hill" in an NBC rendition of her life. She was Sally Sanford, the former madam who became mayor of Sausalito, CA, in "Lady of the House" (NBC, 1978), and starred in the 1984 CBS miniseries "Master of the Game". In 1997, Cannon was a 'Total Woman' talk show host forced to rough it with her husband and two kids in "Beverly Hills Family Robinson" (ABC). Cannon enjoyed a career resurgence when she joined the cast of the popular Fox series "Ally McBeal" (1997-2002) as Judge Whipper Cone, a muture but still sexy jurist who strikes up a torrid affair with lawyer Richard Fish (Greg German). Her next small-screen role was as Honey Bernstein-Flynn, the mother on the short-lived NBC sit-com "Three Sisters" (2000-2002). She next returned to the large screen in the tepid action-comedy "Kangaroo Jack" (2003).