Mahomes was born to parents Pat Mahomes, a former MLB pitcher, and Randi Mahomes on September 17, 1995. Mahomes attended Whitehouse High School in Whitehouse, Texas. He played football, baseball, and basketball. In football, he had 4,619 passing yards, 50 passing touchdowns, 948 rushing yards and 15 rushing touchdowns as a senior. In baseball, he threw a no-hitter with 16 strikeouts in a game his senior year. He was named the Maxpreps Male Athlete of the Year for 2013–2014.