Michael Brian Brennan (born 1963) is a United States Circuit Court Judge of the United States Court of Appeals for the Seventh Circuit. He was first nominated on August 3, 2017, by President Donald Trump, and was re-nominated in 2018. He was confirmed May 10, 2018. He was previously a partner in the Milwaukee law firm Gass Weber Mullins LLC, and served 8 years as a Wisconsin Circuit Court judge.