Frederick Theodore Underwood (October 14, 1868 – January 26, 1906) was a Major League Baseball pitcher during part of the 1894 season.
Underwood appeared in seven games for the Brooklyn Grooms of the National League, starting six of them and completing five.
In his short MLB career he was 2–4 with 10 strikeouts and an ERA of 7.85.
Underwood died at the age of 37 in Kansas City, Missouri.
This biographical article relating to an American baseball pitcher born in the 1860s is a stub.