Alexander "Sandy" Mayer (born April 5, 1952) is a former tennis player from the United States.

He won twelve titles in singles and twenty-four titles in doubles in his professional career, and was part of the winning tennis squad at Stanford University in 1973.

In 1972, Mayer and Roscoe Tanner won the NCAA doubles championship, and the Stanford team finished second in the NCAA tournament, behind Trinity University.

The right-handed Mayer reached his highest singles ATP-ranking in April 1982, when he became world No.

[citation needed] Mayer has four sons and a daughter, all of whom had been previously ranked in the United States Tennis Association Junior Tennis League (Northern California Section).