Samuel Robert Nicholls (15 May 1885 – 26 September 1939) was an Australian politician. Born in Mudgee, New South Wales, he was educated at public schools and became a clerk and cement worker. In 1917, he narrowly defeated Ernest Carr, a Labor turned Nationalist MP, to win the Australian House of Representatives seat of Macquarie for Labor. He held the seat until his defeat in 1922 by Nationalist Arthur Manning. He died in 1939.