William J. Brady | |
|---|---|
 Brady in 1872, Territorial Legislature photograph | |
| Born | August 16, 1829 County Cavan, Ireland |
| Died | April 1, 1878 (aged 48) Lincoln, New Mexico Territory, U.S. |
| Cause of death | Gunshot wound |
| Occupation(s) | Lawman, soldier, politician |
| Years active | 1851–1878 |
| Known for | Lincoln County War |
William J. Brady (August 16, 1829 – April 1, 1878) was an Irish-born American soldier, politician, and corrupt law enforcement officer who served as the sheriff of Lincoln County during the Lincoln County Wars in New Mexico, United States. He was murdered in an ambush, aged 48, by the Lincoln County Regulators and Billy the Kid.