The Town of Ajax was born during the Second World War. At the time, this area was a rural part of the township of Pickering, with nothing more than some farms and little industry. In 1941, Defense Industries Limited established a munitions plant here, and a town grew around the plant, which at its peak employed over 9,000 workers, and was an integral part of the war effort.
The town name is from the British cruiser HMS Ajax, which was a key player during the Battle of the River Plate, the first Allied Naval victory in the war. In December 1939, a flotilla of British warships, including HMS Ajax, HMS Exeter and HMS Achilles, commanded by Commodore Harry Harwood, engaged and crippled the German battleship Admiral Graf Spee near the Uruguayan port of Montevideo. The German ship fled to into the port, but rather than face the overwhelming British force, the Captain scuttled his ship. The Town of Ajax takes its name from this famous battle.