After the disappearance of Harold Holt, Hasluck unsuccessfully stood in the resulting Liberal leadership election. He initially stayed on in cabinet under the new prime minister, John Gorton, but in 1969 Gorton instead nominated him to replace Lord Casey as governor-general. In his five years in the position, Hasluck saw two previous political adversaries (William McMahon and Gough Whitlam) become prime minister; he maintained good working relationships with both. In retirement, he was a prolific author, publishing an autobiography, several volumes of poetry, and multiple works on Australian history.