He was the son of William B. Keane and Hannah Purtill, and was educated at Listowel National School and then St Michael's College, Listowel. He worked as a chemist's assistant between 1946-51, and had various jobs in the UK between 1951 and 1955 - he was a pub owner in Listowel from 1955. He married Mary O'Connor and had four children. He was an Honorary Life Member of the Royal Dublin Society from 1991, served as president of Irish P.E.N. and was a founder member of the Society of Irish Playwrights and a member of Aosdána. He died at his home in Listowel - a popular public house - aged 73 from cancer. In his life Keane published 46 works.
Keane was diagnosed with prostate cancer in 1994 and his condition had deteriorated in recent days.
Keane spent several childhood summers with relations in the nearby Stack Mountains where, he said, he was "half-reared, half-dragged up and countrified".