| William A. Munnell | |
| Office1: | Settlement Judge for the Los Angeles County Superior Court |
| Term Start1: | 1982 |
| Term End1: | 1985 |
| Term Start2: | 1961 |
| Term End2: | 1981 |
| Office3: | Majority Floor Leader of the California State Assembly |
| Term Start3: | 1959 |
| Term End3: | 1961 |
| Office4: | Minority Leader of the California State Assembly |
| Term Start4: | 1957 |
| Term End4: | 1958 |
| Birth Date: | 9 October 1920 |
| Birth Place: | Marshalltown, Iowa |
| Death Place: | Reno, Nevada |
| State Assembly5: | California |
| District5: | 51st |
| Term5: | January 8, 1951 – November 30, 1961 |
| Preceded5: | Elwyn S. Bennett |
| Succeeded5: | John Moreno |
| Party: | Democratic |
| Spouse: | Charlotte Hayduk (m. 1940) |
| Children: | 4 |
| Education: | University of Southern California (JD) 1948 |
| Unit: | Counter Intelligence Corps (Army CIC) |
| Battles: | World War II |
William Arthur Munnell (October 9, 1920 – March 1, 2013)[1] was an American politician who served in the California State Assembly for the 51st district from 1951 to 1961[2] and during World War II he served in the United States Army.[3] While serving in the California State Assembly he was at one point the minority and the majority leader for the Democratic Party. He also served on the Los Angeles County Superior Court from 1961 until 1985.