Brian P. Stack (born May 16, 1966) is an American Democratic Party politician who serves in the New Jersey Senate, where he represents the 33rd Legislative District and serves Chairman of the Senate Judiciary Committee. He has also served as the Mayor of Union City, New Jersey since 2000. Prior to his election to the Senate, he was a part of the lower house of the New Jersey Legislature and the General Assembly from 2004 to 2007. Since 2007, Stack has been widely considered one of the most powerful people in Hudson County, the New Jersey Senate, and North Jersey generally.