The son of Edmund Thomas and Elsie Margaret (Coyle) Keneally, he grows up in Kempsey and is educated at St. Patrick’s College, Strathfield where, subsequently, a writing prize has been named after him. Keneally enters St. Patrick’s Seminary, Manly to train as a Catholic priest. Although he is ordained as a deacon while at the seminary, he leaves without being ordained into the priesthood. He works as a Sydney schoolteacher before his success as a novelist and is a lecturer at the University of New England from 1968–1970.
Keneally is known as “Mick” until 1964 but, upon the advice of his publisher to use his real first name, begins using the name Thomas when he starts publishing. He is most famous for writing Man Booker Prize winner Schindler’s Ark (1982) which is later republished as Schindler’s List, and is later adapted to Steven Spielberg‘s Schindler’s List, which wins the Academy Award for Best Picture. Many of Keneally’s novels are reworkings of historical material, although modern in their psychology and style.
Keneally also acts in a handful of films. He has a small role in The Chant of Jimmie Blacksmith, based on his novel, and plays Father Marshall in the award-winning Fred Schepisi film The Devil’s Playground (1976).
Keneally is a strong advocate of an Australian republic, meaning the abolition of the Australian monarchy, and publishes a book, Our Republic, on the subject in 1993. Several of his Republican essays appear on the web site of the Australian Republican Movement.
Keneally is a keen supporter of rugby league football, in particular the Manly Warringah Sea Eagles club of the National Rugby League. In 2004 he gives the sixth annual Tom Brock Lecture and makes an appearance in the 2007 rugby league drama film The Final Winter.
In March 2009, the Prime Minister of Australia, Kevin Rudd, gives an autographed copy of Keneally’s biography Lincoln to President Barack Obama as a state gift. Recently Keneally has been a featured writer in the critically acclaimed Australian drama Our Sunburnt Country.