John Thomas "Jack" Rimmer (April 27, 1878 - June 6, 1962) was a British athlete, winner of two gold medals at the 1900 Summer Olympics.

Born in Ormskirk, Lancashire, John Rimmer won the British AAA Championships in 4 miles in 1900.

At the Paris Olympics, Rimmer at first participated in the 1500 m, where he finished eighth. On the next day, Rimmer won the gruelling 4000 m steeplechase, beating teammate Charles Bennett by one and half yards. Together with Bennett, Alfred Tysoe, Sydney Robinson and Stanley Rowley , Rimmer won a second Olympic title in 5000 m team race, finishing second behind Bennett.

Rimmer joined the Liverpool City Police in 1901 and retired as sergeant 30 years later. He continiued to run until he was well over the 50 years of age. He was also a president of the famous Sefton Harriers until his death.

John Rimmer died in Liverpool, aged 84.