John Valentine MacDonald (14 February 1880 – 17 August 1937) was a New Zealand-born Australian politician. Born in Opotiki in New Zealand, he was educated in the country before becoming a printer. He migrated to Australia in 1897, becoming a journalist and editor; he was editor of the Brisbane Standard in 1913. He was also a founding member of the Australian Journalists' Association. On 11 July 1922, he was appointed to the Australian Senate as a Labor Senator for Queensland, filling the casual vacancy caused by the death of Nationalist Senator John Adamson. He was defeated in the 1922 election, but was re-appointed on 1 August 1928 following the death of another Nationalist, Senator Thomas Givens. He was defeated again at the 1928 election. MacDonald was finally elected in his own right in the election of 1931, taking his place in the Senate in 1932. He died in 1937, necessitating the appointment of another (in this case, Labor's Benjamin Courtice) to fill his own casual vacancy.