Forrest "Frosty" Thomas (May 23, 1881 – March 18, 1970) was an American baseball right-handed pitcher and medical doctor.

In 1903, Frosty lost 20 games for the Millers, but the following season he turned things around and had a 21–15 record in 329 innings.

In six innings, he gave up eight runs (five earned), and finished his major league career with a record of 0–1 and an earned run average (ERA) of 7.50.

He later played for the Montgomery Senators in the Southern Association (1908-1911), St. Paul Saints (1912), Sioux City Packers (1912), St. Joseph Drummers (1912, 1914-1915), and San Francisco Seals (1913).

He lived for the last 43 years of his life in St. Joseph, Missouri, was employed on the staff of St. Joseph State Hospital for approximately 25 years, and served two terms as Buchanan County coroner.