The 1940 Chatham Cup was the 17th annual nationwide knockout football competition in New Zealand, and the last such competition before the suspension of the Chatham Cup due to World War II. The competition resumed in 1945 as hostilities were drawing to a close. The competition was run on a regional basis, with regional associations each holding separate qualifying rounds. Teams taking part in the final rounds are known to have included Ponsonby, Waterside (Wellington), Hamilton Wanderers, Nomads (Christchurch), and Mosgiel.