| J. Weston Allen | |
| Office: | 25th Attorney General of the Commonwealth of Massachusetts |
| Governor: | Calvin Coolidge Channing H. Cox |
| Predecessor: | Henry A. Wyman |
| Successor: | Jay R. Benton |
| Term Start: | 1920 |
| Term End: | 1923 |
| Office2: | Member of the Massachusetts House of Representatives from the 4th Middlesex district |
| Term Start2: | 1915 |
| Term End2: | 1918 |
| Birth Date: | 19 April 1872 |
| Birth Place: | Newton Highlands, Massachusetts |
| Death Place: | Waverly, New York |
| Alma Mater: | Yale University Harvard Law School |
| Party: | Republican |
| Profession: | Attorney |
| Spouse: | Caroline Cheney Hills (1901–42) |
| Residence: | Newton, Massachusetts |
| Footnotes: | [1] |
John Weston Allen[2] (April 19, 1872[2] – January 1, 1942[3]) was an American politician who served as a member of the Massachusetts House of Representatives from 1915 to 1918[4] and as Massachusetts Attorney General from 1920 to 1923.
As Attorney General, Allen was aggressive in his pursuit of white collar criminals.[5] During his tenure, Allen prosecuted Thomas W. Lawson, L. C. Van Riper,[5] and Charles Ponzi.[2]
Instead of seeking reelection, Allen ran for Governor of Massachusetts in 1922 but lost the Republican primary election to incumbent Channing H. Cox. Allen served as a member of the United States Attorney General's National Crime Commission from 1926 to 1936 and was the commission's chairman from 1930 to 1936.