The 1975 U.S. Pro Indoor was a men's WCT tennis tournament played on indoor carpet courts at the Wachovia Spectrum in Philadelphia, Pennsylvania in the United States. It was the eight edition of the tournament and was held from on January 20 through January 26, 1975. Marty Riessen won the singles title.

Marty Riessen defeated Vitas Gerulaitis 7–6^(7–1), 5–7, 6–2, 6–7^(0–7), 6–3

Brian Gottfried / Raúl Ramírez defeated / Erik Van Dillen 3–6, 6–3, 7–6^(7–4)