The 1975 U.S. National Indoor Tennis Championships was a men's tennis tournament held at the Wicomico Youth and Civic Center in Salisbury, Maryland.

The event was part of the 1975 USLTA-IPA Indoor Circuit.

It was the fifth edition of the tournament and was held from February 10 through February 16, 1975, and played on indoor carpet courts.

Second-seeded Jimmy Connors won the singles title and earned $9,000 first-prize money.

[3][4] Jimmy Connors defeated Vitas Gerulaitis 5–7, 7–5, 6–1, 3–6, 6–0 Jimmy Connors / Ilie Năstase defeated Jan Kodeš / Roger Taylor 7–6, 6–2