Christopher Michael Russo (born October 18, 1959), also known as "Mad Dog", is an American sports radio personality best known as the former co-host of the Mike and the Mad Dog sports radio program with Mike Francesa, which was broadcast on WFAN in New York City and simulcasted on the YES Network. Russo joined Sirius XM Radio in August 2008 and operates his own channel, Mad Dog Sports Radio. He also hosts an afternoon radio show, Mad Dog Unleashed, SiriusXM Ch. 82 Mad Dog Sports Radio. Russo also joined MLB Network on March 31, 2014 and hosted his own show, High Heat, until 2024. He also frequently appears on ESPN’s First Take. Russo was inducted into the Radio Hall of Fame on November 1, 2022.