A native of Pittsburgh, Pennsylvania, Donald attended Penn Hills High School. He was selected first team All-State Class AAAA in each of his final two seasons, and compiled 63 tackles, 15 tackles for loss and 11 sacks as a senior. He also started at offensive guard.
As a freshman, Donald played in all 13 games as a reserve defensive tackle. He recorded 11 tackles, including three for loss, and two sacks. In 2011, as a sophomore, Donald moved into the starting lineup, and turned in a breakout campaign. He recorded 47 tackles, including 16 for loss, 11 sacks and one forced fumble, and was named an second-team All-BIG EAST selection. 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. His senior season, he became one of the productive defensive players in the entire NCAA. He posted 59 tackles, including a career best 28.5 for loss, 11 sacks and four forced fumbles. He was named the ACC Defensive Player of the Year and was a unanimous All-American.
At the NFL Combine, Donald ran the forty yard dash with an official time of 4.62 seconds, setting the record for fastest time for a defensive tackle previously held by Tank Johnson, who ran a 4.69 in 2004. Donald drew comparisons to John Randle afterwards. He was selected by the St. Louis Rams in the first round of the 2014 NFL Draft with the 13th pick overall.