Wagner (born July 24, 1977) is a Democratic Party politician in the United States and is currently serving her second term as Allegheny County Controller.
She was a member of the Pennsylvania House of Representatives for the 22nd District which includes the South Side and part of the North Side of the city of Pittsburgh, and parts of the suburbs of Baldwin, Whitehall and Castle Shannon.
She stepped down from the House when she was elected Allegheny County Controller.
Wagner was first elected to the House in 2006 with over 55% of the vote.
She defeated incumbent Michael Diven, who had switched to the Republican Party earlier that year.Wagner is serving her second term as Allegheny County Controller after she won the Democratic nomination for re-election on May 19, 2015 in a landslide victory over her predecessor and was unopposed in the general election on November 3, 2015, despite being outspent by a margin of 8:1 by the local Democratic establishment.She was named a Governing Magazine 2017 Women In Government Leadership honoree, joining the third cohort of twenty-five members, selected from over 100,000 women holding elected office nationally.