Lattimore was born in Duncan, South Carolina. He attended Florence Chapel Middle School and James F. Byrnes High School in Duncan, and played high school football for the Byrnes Rebels. One of the most decorated players in South Carolina high school football history, Lattimore was ESPN RISE National High School Junior Football Player of the Year in 2008. In his senior year, he earned USA Today high school All-American honors, was named South Carolina’s Mr. Football, and played in the 2010 U.S. Army All-American Bowl. He chose South Carolina over Auburn on National Signing Day.

On September 11, 2010, in just his second career college football game, Lattimore broke 42 tackles on 37 carries, rushing for 182 yards and two touchdowns against the Georgia Bulldogs. On October 9, 2010, against the then #1 ranked Alabama Crimson Tide, Lattimore had 23 carries for 93 yards, two rushing touchdowns, and caught one receiving touchdown from quarterback Stephen Garcia. On October 16, 2010, Lattimore scored two touchdowns in a road loss to the Kentucky Wildcats before missing the rest of the game with an ankle injury. On October 30, 2010, against the Tennessee Volunteers, Lattimore had 29 carries for 184 yards and one rushing touchdown. On November 13, 2010 against the Florida Gators in Gainesville, Lattimore had 40 carries for 212 yards and three rushing touchdowns, to defeat the Gators and clinch the SEC East for the Gamecocks.

On December 4, 2010 in the 2010 SEC Championship Game, Lattimore had 16 carries for 84 yards for the Gamecocks in the 56-17 loss to the Auburn Tigers. In December 2010, Lattimore was named the NCAA Freshman of the Year, headlining the All-Freshman Team, by The Sporting News. On December 31, 2010, in the 2010 Chick-fil-A Bowl, Lattimore had one carry that went for a one-yard loss and caught three passes for 48 yards, before sustaining a concussion in the first quarter on a pass reception in which he lost a fumble in a 26-17 loss to Florida State.

South Carolina began their 2011 season at the Bank of America Stadium in Charlotte on September 3, 2011 against East Carolina. He rushed for 112 yards on 23 carries and added three touchdowns as the Gamecocks battled back to win 56-37. Lattimore also caught three passes for 33 yards.

On December 12, 2012, Lattimore confirmed in a press conference that he would enter the 2013 NFL Draft. On April 27, 2013, he was drafted in the fourth round, with the 131st overall pick, by the San Francisco 49ers. On May 31, 2013, the San Francisco 49ers signed Lattimore to a 4-year deal worth $2,460,584 including a signing bonus of $300,584. On August 27, 2013, he was placed on the reserve/non-football injury list.

On November 5, 2014, Lattimore announced his retirement from the NFL.

In mid-December 2015, Lattimore announced that he would join the staff of newly appointed South Carolina head coach Will Muschamp. Lattimore would not be a coach, but would talk to the players about life off the field, similar to his work at his leadership academies through his foundation. However, in April 2016, the NCAA indicated that the university would gain an unfair recruiting advantage by hiring Lattimore, due to his work with high school kids through his foundation. Lattimore indicated that the NCAA ruling was fair, and that he would not be joining South Carolina’s staff. On May 6, 2016, it was announced that Lattimore would be joining the football staff at Heathwood Hall Episcopal School in Columbia, South Carolina. Lattimore was named head football coach at Heathwood on November 14, 2016. On January 11, 2018 it was announced that Lattimore would be joining Will Muschamp’s coaching staff at South Carolina as Director of Player Development.

On December 19, 2015, Lattimore married his high school sweetheart Miranda Bailey. He is a Christian.