The 1975 Custom Credit Australian Indoor Championships was a men's professional tennis tournament played on indoor hard courts at the Hordern Pavilion in Sydney, Australia and was part of the 1975 Commercial Union Assurance Grand Prix as a Group AA category event. The tournament was held from 13 October through 19 October 1975. Unseeded Stan Smith won the singles title.

Stan Smith defeated Robert Lutz 7–6, 6–2

Brian Gottfried / Raúl Ramírez defeated Ross Case / Geoff Masters 6–4, 6–2