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.

[3][4] Stan Smith defeated Robert Lutz 7–6, 6–2 Brian Gottfried / Raúl Ramírez defeated Ross Case / Geoff Masters 6–4, 6–2