Carter attended Pennsylvania State University, where he was a standout player for coach Joe Paterno's Penn State Nittany Lions football team from 1992 to 1994, along with a strong group of offensive players including future NFL startersJeff Hartings, Joe Jurevicius, Kerry Collins, OJ McDuffie, Bobby Engram and Kyle Brady. Together, this explosive offense propelled the 1994 Penn State team to a 12-0 undefeated season. At Penn State Carter wore the number 32, which previously was worn by running back Blair Thomas. Despite playing only three seasons, he is still in the top ten among Penn State running backs, having compiled 2,829 yards rushing on 395 attempts and scoring 34 touchdowns. His best single game came against the Michigan State Spartans in 1994, when he rushed for 227 yards on 27 carries and scored five touchdowns. Carter helped lead the 1994 Penn State football team to an undefeated record and a berth in the Rose Bowl, was recognized as a consensus first-team All-American, and finished second in the Heisman Trophy voting. He earned co-MVP honors in the Rose Bowl, rushing for 156 yards and three touchdowns on 21 carries. He ran for an 83-yard touchdown on the first offensive play of the game, which is the third-longest run in Rose Bowl history and the longest run in Penn State bowl history. Carter also added touchdown runs of 17 and three yards in the third quarter. The Rose Bowl was Carter's final game as a Nittany Lion, as he was encouraged by Paterno to forgo his senior season and enter the NFL Draft. "This is the first time I have told anybody who has not graduated that I felt they ought to leave," Paterno said. The Tournament of Roses Association announced his induction into the Rose Bowl Hall of Fame as a member of the Class of 2014, a ceremony that took place in December 2014.
Carter signed a seven-year, $19.2 million deal which included a $7.125 million signing bonus, which at the time was an NFL record contract for a rookie. There were also incentive clauses such as making an extra $100,000 if he scored 12 touchdowns in a season.
He played for the Washington Redskins in 2001, and the New Orleans Saints from 2003 to 2004. In seven NFL seasons, he played in 59 games, started 14 of them, and compiled 1,144 rushing yards and 20 touchdowns on 319 attempts, and 66 receptions for 469 yards and a touchdown.