| Alonzo B. Cook | |
| Birth Date: | July 31, 1866 |
| Birth Place: | Boston, Massachusetts, U.S. |
| Death Place: | Boston, Massachusetts, U.S. |
| Nationality: | American |
| Party: | Republican Economy |
| Massachusetts Auditor | |
| Term Start: | 1915 |
| Term End: | 1931 |
| Governor: | David I. Walsh Samuel W. McCall Calvin Coolidge Channing H. Cox Alvan T. Fuller Frank G. Allen |
| Successor: | Francis X. Hurley |
| Alma Mater: | Sherwin Grammar, Roxbury High School, University Law School |
Alonzo B. Cook (July 31, 1866 – December 22, 1956) was an American politician who served as Massachusetts Auditor from 1915 to 1931 and was a candidate for Mayor of Boston in 1925 and in 1937; and United States Senator in 1936.
He was born on July 31, 1866, to Levi F. Cook and Eliza Ryan. One of his brothers, Washington Cook, was also involved in politics.[1] [2]