William Mills Maltbie (born Granby, Connecticut, March 10, 1880; died in Granby December 15, 1961) was a lawyer, judge, and chief justice of the Connecticut Supreme Court.
On graduation he was admitted to the bar and joined his father's practice in Hartford.
While still assistant state's attorney, Maltbie served as Governor Marcus H. Holcomb's executive secretary from 1915 to 1917.
Following his retirement from the bench he served as a state referee and conducted two one-man grand jury investigations, in 1951 and 1954.
Maltbie did extensive work with the Boy Scouts of America (as a member of the national council), the YMCA, the Probation Association, the Connecticut Prison Association (long-time president), the Connecticut Opera Association (president), the Greater Hartford Federation of Churches (president), and other charitable and non-profit organizations.