James Norman "Mad Dog" Mattis (born September 8, 1950) is a retired United States Marine Corps general and was the 26th United States Secretary of Defense. On January 20, 2017, the United States Senate confirmed Mattis' nomination as Defense secretary with a 98-1 vote. He last served as the 11th Commander of United States Central Command from August 11, 2010 to March 22, 2013.

On December 20, 2018, Mattis announced his plans to retire on February 28, 2019. However after reading his resignation letter criticizing Trump's treatment of American allies, Trump ordered Mattis fired on December 31, 2018.