| Bill Diamond | |
| Office: | Member of the Maine Senate |
| Term Start: | December 3, 2014 |
| Term End: | December 7, 2022 |
| Predecessor: | Rodney Whittemore |
| Successor: | Timothy Nangle |
| Constituency: | 26th district |
| Term Start1: | December 2004 |
| Term End1: | December 2012 |
| Successor1: | Gary Plummer |
| Constituency1: | 12th district |
| Office2: | 45th Secretary of State of Maine |
| Governor2: | John R. McKernan Jr. Angus King |
| Term Start2: | 1989 |
| Term End2: | 1996 |
| Predecessor2: | Rodney S. Quinn |
| Successor2: | Dan Gwadosky |
| Party: | Democratic |
| Spouse: | Jane Diamond |
| Alma Mater: | University of Southern Maine, Gorham University of New England |
G. William Diamond (born 1945) is an American Democratic politician, educator, small business owner, legislator and former Maine Secretary of State. Diamond currently serves in the Maine Senate representing Senate District 26, which comprises the towns of Windham, Raymond, Standish, Casco, Baldwin and Frye Island.
Diamond served in the Maine House of Representatives from 1977 to 1982, was the Maine Secretary of State from 1989 to 1997, and has served in the Maine Senate from 1982 to 1986, from 2004 to 2012 and from 2018 to the present. He was a teacher in the Windham and Raymond school systems for 18 years and was the superintendent and director of governmental relations for the controversial Élan School in Poland, Maine.
Diamond was born in 1945. He received a bachelor's degree from Gorham State Teachers' College in 1968 and a master's degree in education administration from the same institution in 1972. He was a teacher and principal in the Windham and Raymond school system from 1968-1986, and was the superintendent of the Raymond school system in 1986. Diamond has been a business owner since 1980.
Diamond also served as the superintendent and director of governmental relations at the Élan School in Poland, Maine, which closed in 2011 following an online campaign against the school over its alleged abuse and mistreatment of students.
Diamond first ran for Maine House District 23 in 1976, winning the Democratic primary as a write-in candidate and defeating Republican Barbara Strout 51%-49% in the general election. He served two subsequent terms, running unopposed in Democratic primaries in both 1978 and 1980, defeating Republican Carole Bean in the 1978 general election and running unopposed in the 1980 general election.
In 1982, Diamond defeated Republican David Huber 56%-44% in the general election to represent Maine Senate District 6. He won a second Senate term in 1984, beating Republican Kenneth Cole 61.5%-38.5%.
Diamond was first elected Secretary of State by the 114th Maine House of Representatives on December 7, 1988. Diamond was nominated along with Stephen M. Zirnkilton and received 115 House votes to Zirnkilton's 62. Diamond's first two-year term as Secretary of State began in 1989 under Governor John R. McKernan Jr.
In 1993, Diamond faced criticism for his response to a ballot-tampering accusation directed toward an assistant to then-House Majority Leader John L. Martin. The incident is credited with contributing to the establishment of term limits for Maine legislators later in 1993.
Diamond entered the race for Maine's 1st congressional district in 1994 but lost the Democratic primary election. He remained Secretary of State until 1997 under Governor Angus King.
Diamond again ran for the Senate District 12 seat in 2004. He ran unopposed in the Democratic primary and defeated Republican Joseph Bruno 55%-45% in the general election. He was re-elected in 2006, 2008, and 2010 before reaching his term limit.
In 2014, Diamond again sought the Senate District 26 seat, ran unopposed in the Democratic primary and defeated Republican Kaile Warren 63%-37% in the general election. He was re-elected in 2016, 2018 and 2020.
Diamond and his wife, Jane Diamond, live in Windham. They have two adult daughters and eight grandchildren. In 2012, Diamond published The Evil and the Innocent, a compilation of true crime stories about perpetrators and victims of child sexual abuse.
Diamond has been the co-founder and president of Windham Neighbors Helping Neighbors since 2007 and serves on the board of directors for the Maine State Society for the Protection of Animals and for Hospice of Southern Maine.
(Diamond served as the Maine Secretary of State from 1989 to 1997.)