[2][3][4] Donald played college football for the Pittsburgh Panthers, where he won the Bronko Nagurski, Outland, and Bill Willis trophies and the Chuck Bednarik and Lombardi awards as senior.

During his NFL career, Donald was named Defensive Player of the Year a record three times, along with receiving Pro Bowl selections in all ten of his seasons and eight first-team All-Pro honors.

He recorded 47 tackles, including 16 for loss, 11 sacks and one forced fumble, and was named a second-team All-Big East Conference selection.

[11] As a junior, he recorded 64 tackles, including 18.5 for loss, 5.5 sacks, and one forced fumble, earning first-team All-Big East honors.

[13][14] At the NFL Combine, Donald set the record for fastest 40-yard dash time for a defensive tackle with a 4.68.

[23] On June 16, 2014, the Rams signed Donald to a four-year, fully guaranteed $10.13 million rookie contract.

[24] On September 7, 2014, Donald made his regular season debut against the Minnesota Vikings and finished the 34–6 loss with four tackles.

During the season opener against the Seattle Seahawks, he finished with nine total tackles and two sacks, helping the Rams win 34–31 in overtime.

[32] He was named National Football Conference (NFC) Defensive Player of the Week for the first time in his NFL career for his performance.

[36] Donald started all 16 games, ending the season with 69 tackles, 11 sacks, a pass defended, and a fumble recovery.

[40] On September 12, 2016, Donald was ejected for making illegal contact with a referee in a 28–0 shutout road loss to the 49ers on Monday Night Football.

[43] During a Week 4 17–13 victory over the Arizona Cardinals, Donald had 1.5 sacks, five total tackles, one tackle-for-loss, five quarterback hits, and a forced fumble.

In the next game against the 49ers, he recorded three tackles and sacked Brian Hoyer in the fourth quarter to seal a 41–39 road victory for the Rams.

[59] The deal made him the highest paid defensive player in NFL history, until Khalil Mack signed a $141 million contract with the Chicago Bears the next day after being traded from the Oakland Raiders.

[71] Donald helped the Rams defeat the Dallas Cowboys in the Divisional Round and the New Orleans Saints in the NFC Championship to reach the Super Bowl.

[72][73] In Super Bowl LIII Donald recorded five tackles but the Rams lost by a score of 13–3 to the New England Patriots, with the Patriots offensive linemen (including Joe Thuney) double teaming Donald in order to neutralize his effectiveness which was cited as a key factor in the result.

[78] During Week 3 against the Cleveland Browns, Donald recorded his first sack of the season on Baker Mayfield in the 20–13 road victory.

[80] In the next game against the Atlanta Falcons, Donald recorded a strip sack on Matt Ryan and recovered the football in the 37–10 road victory.

[93] In Week 12 against the 49ers, Donald recorded a sack on Nick Mullens and forced a fumble on running back Raheem Mostert that was recovered and returned by teammate Troy Hill for a touchdown during the 23–20 loss.

[102][103] Similar to what happened in Week 12, Donald choked D. J. Humphries in the Wild Card Round against the Cardinals and threw a punch.

[107] In Super Bowl LVI against the Cincinnati Bengals, Donald had two sacks and three quarterback hits, including the game-sealing pressure play on fourth-and-1 with less than a minute remaining that resulted in an incompletion and the 23–20 win.

[112][113][114] Donald suffered an ankle sprain during a road loss against the Kansas City Chiefs in Week 13.

[122][123] In a July 2024 interview with former Miami Dolphins linebacker Channing Crowder, Donald cited already feeling more than accomplished in the sport and no longer having the desire or passion to continue the persistent training as reasons for his retirement at just 32 years old.

Donald's older brother, Archie Jr., was a star linebacker at Toledo who "bounced around the NFL as an undrafted free agent until retiring in 2012".

[127] The brothers, who shared bunk beds in their childhood, frequently thought about one day helping their parents retire, which became one of the driving forces in Aaron's career.