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 has also served as the Mayor of Union City, New Jersey since 2000. Prior to his election to the Senate, he served in the lower house of the New Jersey Legislature, the General Assembly from 2004 to 2008.He is considered by PolitickerNJ to be one of the most powerful elected officials in Hudson County, New Jersey.