Born Frederick George Peter Ingle-Finch in London, he lived as a child in France and India, and finally in Australia, his parent's native country. There he grew up in Sydney.

After finishing school, he worked in several badly-paid jobs until he tried acting. He began in 1935 playing theatre roles, and also working in radio. In 1938, he appeared in his first film, Dad and Dave Come to Town.

Thereafter he played again on stage, where he was noticed by Laurence Olivier and encouraged to return to London. During this time Finch had an affair with Olivier's wife, Vivien Leigh.

Despite his stage experience, Finch suffered from stage fright and turned to films. His first role in a British-made film was in Eureka Stockade (1949) (set in Australia).

Finch's Hollywood debut was in The Miniver Story in 1950, but his first major role was in 1956's A Town Like Alice.

In 1972, his role of the homosexual Jewish doctor in Sunday Bloody Sunday earned him an Academy Award nomination for Best Actor in a Leading Role.

Jon Finch, an actor with whom Peter Finch is often confused but who was unrelated to Peter, also appeared in a minor role in the film.

He also won an Oscar for his over-the-top portrayal of the crazed television anchor man Howard Beale in the 1976 film Network.

He died from a stroke, aged 60, during a promotional tour for the film. He nevertheless won the Oscar, the first time the Best Actor award had been made posthumously, and he was the first Australian actor to win the award. It was accepted by his widow.

Finch also won five Awards of the British Film Academy.

Peter Finch was married three times. His fist wife was Tamara Tchinarova and his second wife Yolande Turner. Both marriages ended in divorce. His third wife was Eletha Finch. He had four children from his three marriages.

He is interred in the Hollywood Forever Cemetery in Hollywood, California.

Some references say his original name was William Mitchell. This is not correct. He was once arrested for drunkenness in Rome and, when asked for his name, he gave a fictitious one in order to protect his professional reputation. When his real identity was later revealed, some commentators made the incorrect assumption that William Mitchell must have been his legal name.

In 1980, noted author and film/theatre industry insider Elaine Dundy wrote his biography titled Finch, bloody Finch: A biography of Peter Finch.