Anna M. Rivers (born 1965 or 1966) is an American politician and educator serving as a Republican member of the Washington State Senate from when she was appointed to represent the 18th district in 2012, upon the resignation of Joe Zarelli. Prior to this she was a member of the Washington House of Representatives. In her first full term, a Majority Coalition Caucus was formed, taking control away from the Democrats in the state senate. Rivers was appointed to be majority whip for the session, a rare appointment for a freshman senator. She won re-election for another four-year term in 2012, with 67% of the vote against 32% for her opponent, Ralph Schmidt.