Top Ten Math Majors known for something else:

Ralph Abernathy, civil rights leader, BA in math from Alabama State University.

Harry Blackmun, former supreme court justice, BA in math from Harvard.

Lewis Carroll (Charles Lutwidge Dodgson), writer and logician. Held the Christ Church Mathematical Lectureship at Oxford for twenty-six years.

David Dinkins, former mayor of NYC, BA in math from Howard University.

Art Garfunkel, singer, MA in math from Columbia.

Danica McKellar, actress, BA in math from UCLA.

William J. Perry, former secretary of defense, BA and MA in math from Stanford, Ph.D. in math from Pennsylvania State University.

The Simpsons: The writing team for this long-running animated comedy is dominated by math majors;
J. Stewart Burns, BA in math from Harvard; Al Jean, BA in math from Harvard;
Ken Keeler, Ph.D. in math from Harvard;
even the composer, Alf Clausen, minored in math.
The other writers all have backgrounds in physics or computer science.

Dean Smith, college basketball coach, BA in math from University of Kansas.

Virginia Wade, tennis champion (Wimbledon, 1977), BA in math and physics, Sussex University.

Larry Niven, science fiction writer, BA in math from Washburn University.

. . . but this one goes to eleven. . .