William Joseph Mills was an American jurist who served three terms as the chief justice of the New Mexico Territorial Supreme Court and as the 18th and final governor of New Mexico Territory.
- Occupation
- lawyer, judge, politician, governor
- Position held
- Member of the Connecticut House of Representatives, member of the State Senate of Connecticut, Governor of the Territory of New Mexico
- Citizenship
- United States
- Born
- January 11, 1849
- Died
- December 24, 1915