Lorne Hyman Greene was born in Ottawa, Ontario to Russian Jewish immigrants, and began acting while attending Queen's University in Kingston. He gave up on a career in chemical engineering and, upon graduation, found a job as a radio broadcaster for the Canadian Broadcasting Corporation (CBC). He was assigned as the principal newsreader on the CBC National News. The CBC gave him the nickname "The Voice of Canada"; however, his role in delivering distressing war news in sonorous tones following Canada's entry into World War II in 1939 caused many listeners to call him "The Voice of Doom". He also narrated documentary films, such as the National Film Board of Canada's Fighting Norway (1943).

The first of his American television roles was as family patriarch Ben Cartwright on the long-running western series Bonanza (1959-1973), making Greene a household name. He garnered the role after having turned in a highly-regarded performance as Big Brother in a production of Nineteen Eighty-Four for the Columbia Broadcasting System (CBS). After the cancelation of Bonanza, he was host for the CBS nature documentary series "Last of the Wild" from 1974 to 1975.

Greene's next best-known role was Commander Adama, another patriarchal figure, in the science fiction feature film and television series Battlestar Galactica (1978-1979) and Galactica 1980 (1980). The part of leader of the surviving remnant of humanity seemed particularly well suited to Greene.

In 1964, Greene had a #1 single on the music charts with his hit ballad, "Ringo." He was also known as the host and narrator of the nature series, Lorne Greene's New Wilderness. He also appeared in the HBO mockumentary The Canadian Conspiracy, about the supposed subversion of the United States by Canadian-born media personalities. For nearly a decade, Greene co-hosted the Macy's Thanksgiving Day Parade on NBC. He is also fondly remembered as the founder of Toronto's Academy of Radio Arts which had been founded as the Lorne Greene School of Broadcasting.

He was made an Officer of the Order of Canada on October 28, 1969, "For services to the Performing Arts and to the community." Greene was the 1987 recipient of the Earle Grey Award for Lifetime Achievement at the Canadian Gemini Awards. He has a star on the Hollywood Walk of Fame at 1559 N. Vine Street.

He was married twice, to Rita Hands (1938-1960, divorced) and to Nancy Deale (1961-1987, Greene's death). He has two children by Rita Hands, Belinda Susan Bennet (née Greene) and Charles Greene, and one child by Nancy Deale, Gillian Greene.

Greene died of pneumonia in 1987 in Santa Monica, California. He was interred at Hillside Memorial Park Cemetery, Culver City, California. Only weeks before his death, he had been signed to appear in a revival of Bonanza.