William Boyett (January 3, 1927 – December 29, 2004) was an American actor best known for his work as the low-key but authoritative Sergeant William 'Mac' MacDonald on the police drama Adam-12. Adam-12 executive producer Jack Webb selected him for the role after several performances in both iterations of Webb's Dragnet (Boyett can also be seen uncredited as a Baliff in the 1954 movie version).