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. Stan Smith won the singles title.
Stan Smith defeated Robert Lutz 7–6, 6–2
- It was Smith's 6th title of the year and the 55th of his career.
Brian Gottfried / Raúl Ramírez defeated Ross Case / Geoff Masters 6–4, 6–2
- It was Gottfried's 13th title of the year and the 21st of his career. It was Ramírez's 15th title of the year and the 24th of his career.