Florida State senior Nick O'Leary and Miami senior Clive Walford are the other finalists.
Williams leads the Gophers in receptions (28), receiving yards (418), receiving touchdowns (seven) and receiving yards per game (41.8). He leads all conference tight ends in those categories.
Of the finalists, Williams accounts for the largest percentage of his team's receiving yardage and receiving touchdowns.
According to the Pioneer Press, Williams' seven touchdown catches make up 64 percent of the Gophers' receiving touchdowns. Additionally, 22 of his 28 receptions have resulted in first downs.
Williams has won the Mackey Award weekly recognition twice this season.
The first time he won the weekly award followed Minnesota's victory over Michigan when Williams caught four passes for 51 yards and a touchdown, including this spectacular one-handed catch.
He also won the weekly award following a three-touchdown performance in the Gophers' victory over Iowa.
Williams already holds the Gophers' season record for touchdown receptions by a tight end and he is tied with Ron Johnson for the sophomore receiving touchdown record.
If he were to win the award he would become the second Gopher tight end to win the award. Matt Spaeth, who is now with the Pittsburgh Steelers, won the Mackey Award in 2006.
The award's selection committee will announce the winner Dec. 10. The trophy will be presented live at the Home Depot College Football Awards Red Carpet Show on Dec. 11.