Porter was born in Brisbane, Australia, in 1929. His mother, Marion, died of a burst gall-bladder in 1938. He was educated at the Anglican Church Grammar School (then known as the Church of England Grammar School) and left school at eighteen to work as a trainee journalist at The Courier-Mail. However, he only lasted a year with the paper before he was dismissed. He emigrated to England in 1951. On the boat he met the future novelist Jill Neville. Porter was portrayed in Neville's first book "The Fall Girl" (1966). After two suicide attempts, he returned to Brisbane. Ten months later he was back in England. In 1955 he began attending meetings of "The Group." It was his association with "The Group" that allowed him to publish his first collection in 1961.
He married in 1961 and had two daughters (born in 1962 and 1965). Porter's wife, the former Shirley Jannice Henry, committed suicide in 1974, and was found dead in her parents' house in Marlow, Buckinghamshire. In 1991 Porter married Christine Berg, a child psychologist. In 2001, he was named Poet in Residence at the Royal Albert Hall. In 2004 he was a candidate for the position of Professor of Poetry at Oxford University. In 2007, he was made a Royal Society of Literature Companion of Literature, an honour bestowed on a maximum of ten living writers.
Porter died on 23 April 2010, aged 81, after suffering from liver cancer for a year. After news of Porter's death in 2010, the Australian Book Review announced it would rename its ABR Poetry Prize the Peter Porter Poetry Prize in honour of Porter.