Thomas C. O'Brien
| Thomas O'Brien | |
|---|---|
| District Attorney of Suffolk County | |
| In office 1922–1927 | |
| Preceded by | Joseph Pelletier | 
| Succeeded by | William J. Foley | 
| Personal details | |
| Born | June 19, 1887 Boston, Massachusetts, U.S. | 
| Died | November 22, 1951 (aged 64) Boston, Massachusetts, U.S. | 
| Political party | Democratic (Before 1935) Union (1935–1936) | 
| Education | Harvard University (BA, LLB) | 
Thomas Charles O'Brien (June 19, 1887 – November 22, 1951) was an American attorney and politician who served as District Attorney of Suffolk County, Massachusetts and was the United States vice-presidential nominee for the Union Party in the 1936 United States presidential election.