| Frederick Westervelt | |
| Birth Name: | Frederick Euphenia Westervelt |
| Birth Date: | 18 February 1878 |
| Birth Place: | Hackensack, New Jersey |
| Death Place: | Drexel Hill, Pennsylvania |
| Employer: | American League, Federal League, National League |
| Occupation: | Umpire |
| Years Active: | 1911-1912 (AL), 1915 (FL), 1922-1923 (NL) |
Frederick Euphenia Westervelt (February 18, 1878 – May 4, 1955) was a professional baseball umpire who worked in three major leagues for parts of five years. Westervelt umpired in the American League in 1911 and 1912, the Federal League in 1915 and the National League in 1922 and 1923. He umpired 345 major league games.[1] He was a relative of Giants' pitcher, Huyler Westervelt.