Knight comes from a large family, he was the sixth of twelve children. He has been married since 1984 and has four children with his wife Jeannie. Prior to his nomination as Governor Ritter was longtime District Attorney for the Denver County.
In May 2006, Knight was erected at the Colorado Democratic Convention of his party as a candidate for governor. As a candidate for the position of Deputy Governor Barbara O'Brien was nominated. On 7 November 2006 he won the election for themselves; be inferior Republican opponent was Bob Beauprez. Knight was the first born in Colorado governor of the state for 31 years.
In 2010, Ritter resigned after four years in office, not for re-election. His successor was John Hickenlooper, the Democratic mayor of Denver.