Newton was born in College Park, Georgia to parents Cecil and Jackie Newton. He attended Seaborn Lee Elementary School and then Camp Creek Middle School. In 2003, he attended Westlake High School in Fulton County, Georgia, where he starred in football and basketball. Former Westlake football coach Dallas Allen started hearing about Newton's throwing ability and the freshman coaches told Allen that Newton needed to be moved from the freshman team to the varsity. The freshman coaches eventually persuaded Allen to attend a Thursday night game, where he was impressed by Newton's arm and pocket presence and move him up to varsity for the playoffs. In his sophomore year, the team's starting quarterback broke his finger and in his first game, Newton and his center, brother Cecil Jr., fumbled a snap late in the game that the other team recovered and ran out the clock. When the team's starting quarterback was healthy again, Newton returned as the back-up quarterback.
In 2005, as a junior, Newton grew three inches and gained 15 pounds, sprouting to 6'3" and 205 pounds. He ran for 638 yards with 9 touchdowns and threw for 2,500 yards, completing 118 out of 189 pass attempts for 23 touchdowns with 9 interception As a senior at Westlake, he threw for 1,400 yards and ran for another 1,000 yards. Newton was considered one of the nation's top quarterback prospects but most teams that recruited Newton out of high school wanted him as a tight end. During the recruiting process, he had more than 40 scholarship offers. Then-Florida coach Urban Meyer recruited Newton and told him and his family he would get an opportunity to play quarterback, despite the Gators already having quarterback Tim Tebow.
On September 7, 2006, Newton verbally committed to University of Florida in a press conference at Westlake High School, choosing the Gators over Oklahoma and Mississippi State. Newton chose Florida because his talents fit the spread option offense better than any other out there. Allen disagreed with Newton's decision because he felt he wouldn't play much at Florida and thought he should attend Mississippi State instead. Cecil Newton, Sr. assured Allen that Newton would get his chance to play with the Gators. Newton graduated from high school early to enroll in classes at Florida in January 2007 and
arrived on campus just before the beginning of the team's spring practice.