He also played for the Kansas City Chiefs and Baltimore Ravens, making a Pro Bowl appearance in 2014 with the Eagles.

[5] Maclin, paired with Heisman Trophy finalist quarterback Chase Daniel, helped lead the Missouri Tigers to a 12–2 record and victory in the 2008 Cotton Bowl Classic.

[7] Maclin began his second season with the Tigers with high expectations and possible consideration for the Heisman Trophy.

In the Tigers’ season-opener against the Illinois Fighting Illini, he returned a kickoff for a touchdown but left the game with an ankle injury.

[12] * school record + NCAA freshman record Source:[13] Maclin was considered a top National Football League prospect following his second season at Missouri,[14] and roommate Sean Weatherspoon hoped to convince Maclin to return for his junior year instead of leaving Missouri for the 2009 NFL draft.

[16][17][18] Draft analyst Mel Kiper Jr. projected Maclin to go to the Oakland Raiders with the tenth pick in the first round of the NFL Draft,[19] Maclin's personal best in the 40-yard dash was 4.31 seconds, but he wanted to lower that to 4.29 seconds in the NFL Scouting Combine in Indianapolis.

Maclin was the third receiver to be selected in the draft, behind Darrius Heyward-Bey, who went seventh overall to the Oakland Raiders, and Michael Crabtree, who went tenth overall to the San Francisco 49ers.

[31] Maclin started in his first NFL game on September 27, 2009, against the Kansas City Chiefs in week 3 in place of the injured Kevin Curtis.

[32] On October 11, 2009, Maclin scored his first NFL career touchdown on a 51-yard reception from Donovan McNabb as the Philadelphia Eagles beat the Tampa Bay Buccaneers 33–14.

[33] On December 27, 2009, in a home game against the Denver Broncos and with the score tied 27–27, Maclin made a decisive catch on the sideline to extend a crucial late drive for the Eagles.

Three plays later, Eagles kicker David Akers kicked the game-winning field goal, sealing victory for Philadelphia by a score of 30–27.

On January 9, 2010, in the Wild Card Round against the Dallas Cowboys, Maclin became the youngest player to score a touchdown in NFL postseason history, aged 21 years and 243 days.

On August 5, head coach Andy Reid said that he expected Maclin to be healthy for the regular season.

In Week 2, Maclin caught 13 passes with 171 yards and 2 touchdowns but lost to the Atlanta Falcons by a score of 31–35.

[44] On July 27, 2013, Maclin suffered a torn ACL during training camp and was forced to miss the entire 2013 season.

Since the release of DeSean Jackson, as well as a disappointing season by 2013 starter Riley Cooper, Maclin's role on the team had increased as the first-choice receiver.

On January 16, 2015, Maclin was added to the Pro Bowl as an alternate replacing an injured Denver Broncos wide receiver Demaryius Thomas.

Maclin started out slow, but had eight receptions for 141 yards in a Week 3 matchup against the Packers, where he became the first Chiefs wide receiver to catch a touchdown pass since 2013.

[63] On September 10, in the season opening 20–0 victory over the Cincinnati Bengals, Maclin, in his Ravens debut, recorded his first touchdown with the team, which was a 48-yard reception from quarterback Joe Flacco.

On April 25, 2021, his wife Adia, gave birth to his second daughter Krew Sophia Maclin.