Theodore Calvin Arnott (born April 8, 1963) is a politician in Ontario, Canada. He was first elected to the Legislative Assembly of Ontario on September 6, 1990, representing the Riding of Wellington. He is a member of the Progressive Conservative Party of Ontario and represents the Riding of Wellington—Halton Hills in the Ontario Legislature. Arnott has served as Speaker of the Legislative Assembly of Ontario during the 42nd and 43rd Parliaments of Ontario.