The 1978 St. Louis Tennis Classic, also known as the St. Louis WCT, was a men's professional tennis tournament that was part of the World Championship Tennis series of tournaments that were incorporated into the 1978 Grand Prix circuit. It was played on indoor carpet courts at the Checkerdome in St. Louis, Missouri in the United States. It was the eighth and last edition of the tournament and was held from February 6 through February 12, 1978. Unseeded Sandy Mayer won the singles title and earned $30,000 first-prize money.[1]
Sandy Mayer defeated John Alexander 7–6(7–3), 6–4
Bob Hewitt / Frew McMillan defeated 
Wojciech Fibak / Tom Okker 6–3, 6–2