William Cotter, 61, of Belmont, Massachusetts, passed away peacefully on Saturday, October 14, 2017 at home. Born in Cambridge, MA to Chester and Edna Cotter he lived most of his life in Belmont. Billy was a passionate man who worked in the HVAC field for years. In his spare time he enjoyed the Grateful Dead, the Boston Bruins and watching TV (especially wilderness survival shows). Billy was extremely loving and proud of his two sons Eric Cotter of Belmont, and Cory Cotter of Arlington. He is also survived by his Brother Robert Cotter, of Ashburnham; his wife, Nancy (Sheffield) Cotter of Ashburnham; and their three children Jennifer Hanmore (Cotter), Jillian Cotter, and Christoper Cotter. He also leaves behind his long time girlfriend Christine Baker, his close friend and mother of his children Janet Anderson, and his Dog Tennessee (Tee). The family will receive friends on Monday, October 23, 2017 from 6:00PM until 8:00 PM at the DeVito Funeral Home, 761 Mount Auburn Street Watertown, MA. 02472. Followed by a Celebration of life at Donohue's Bar and Grill, 87 Bigelow Ave Watertown, MA. From 8:00pm until 10:00pm. The family would appreciate donations for funeral expenses in lieu of flowers.