Frederick Winthrop Thayer (August 14, 1854 – September 17th, 1913) was an American baseball manager known for inventing the catcher's mask.

While managing the baseball team, Thayer's catcher, Jim Tyng, was frequently being hit in the head with the ball during games.

In the winter of 1876, Thayer went to a local tinsmith to construct a "bird cage" like mask with padding to the chin and forehead.

The invention gained so much attention that the leading sporting goods dealer in America at the time, Spalding, began selling them for 3 dollars in their catalogue.

In 1883, Thayer sued Spalding for patent infringement, and the company was ultimately forced to pay royalties.