Donald beat out Alabama linebacker, Missouri defensive end and UCLA linebacker for the award given annually to the nation's top college lineman.
It's already been a big week for Donald, a senior defensive tackle who won the Bronko Nagurski award given to the nation's top college defensive player Monday.
''It's a true blessing and a true honor for people to notice me and notice the hard work I put into this game,'' Donald said.
The 6-foot, 285-pound Donald leads the nation with 26 1/2 tackles for losses and his 28 1/2 career sacks are tops among active players in the Football Bowl Subdivision and fourth in school history.
Donald has 10 sacks, 54 tackles and has forced four fumbles this season.
Though Pittsburgh is headed to the play Bowling Green in the Little Caesars Pizza Bowl on Dec. 26, Donald was disappointed that his 6-6 team didn't do better.
''The record doesn't show what we wanted as a team,'' Donald said. ''I just went out there and tried to do my job, and that's play football fast and physical and try to make plays to help my team win.''
Mosley was another finalist who was left disappointed by the way the season went for his team. The Crimson Tide was knocked out of a chance to play for a third consecutive national title after losing to Auburn. Mosley will end his college career when Alabama meets Oklahoma on Jan. 2 in the Sugar Bowl.
He leads Alabama with 102 tackles, has seven tackles for losses and broke up five passes.
''I'm not happy with the way it ended,'' Mosley said about the season, ''but we've got one more game to go and I want to go out as a winner for my senior year.''
Sam, who grew up in nearby Hitchcock, Texas, enjoyed returning to his home state for the ceremony.
''It was just a warm feeling when I saw the sign that said: 'Welcome to Texas,' '' he said. ''My family is excited and so proud right now.''
Sam became the first player from Missouri to be a finalist for the Lombardi Award after piling up 18 tackles for losses and 10 1/2 sacks. He also returned a fumble for a touchdown.
Barr is tied for fifth in the nation with 20 tackles for losses. He also has 10 sacks, 62 tackles and forced five fumbles this season. He was honored to be a finalist for the award.
''It means that my hard work has paid off and just to be mentioned with these three other guys has been awesome,'' he said.