John G. Mulroe (born July 21, 1959) is a judge of the Circuit Court of Cook County and lawyer from Chicago, Illinois. Between August 2010 and June 2019, he was a Democratic state senator, representing the 10th Illinois State Senate District. He was appointed to complete the term of Democrat James DeLeo in August 2010 and elected to a full term in the Illinois State Senate in November 2010. He served in the position for nearly nine years before leaving the Illinois Senate in 2019. Robert Martwick replaced Mulroe in the Illinois Senate.