Devon Hall added 15 points, Ty Jerome provided 12 points and six assists and De'Andre Hunter had 10 points for Virginia, which won the tournament crown for the second time in five years.
The Cavaliers (31-2) likely will land the No. 1 overall seed for the NCAA Tournament.
Luke Maye's 20 points paced North Carolina, while Joel Berry II finished with 17 points and Kenny Williams had 12. The sixth-seeded Tar Heels (25-10) were hoping to become the second team in as many years to win four games in four days in the ACC Tournament after Duke did it last March.
Virginia built a 48-39 advantage early in the second half. The Tar Heels responded with a 7-0 run before Guy sank a jumper.
North Carolina went more than 4 1/2 minutes without a scoring, but empty possessions from Virginia kept it interesting.
It was 58-49 after Hunter's short jumper beat the shot clock for Virginia. At the other end, Maye scored his first points of the second half on a 3-pointer with 3:17 to play.
Virginia's Jerome and North Carolina's Berry II traded 3-pointers before the Cavaliers put it away.
Virginia led 34-30 at halftime after North Carolina posted the final six points of the first half.
The Cavaliers built an early seven-point lead and later were up 34-24 for their largest lead.
Maye poured in 15 in the first half. Virginia reserve Nigel Johnson had eight points in the first 12 minutes but didn't score again.
Both teams had six 3-pointers among their 10 first-half field goals. Four of Virginia's first six field goals were 3-pointers. Overall, the Cavaliers were 9 of 17 from beyond the arc while the Tar Heels were 10 of 25.
This was a repeat of the 2016 ACC title game, which was won by North Carolina in Washington.
This season, Virginia won at home in the only regular-season meeting with North Carolina, in January.
--Field Level Media
North Carolina | Virginia | |
Luke Maye 20 | Scoring | Kyle Guy 16 |
Theo Pinson 6 | Assists | Ty Jerome 6 |
Theo Pinson 8 | Rebounds | Ty Jerome 6 |
Joel Berry II 3 | Free Throws Made | De'Andre Hunter 8 |
Joel Berry II 1 | Steals | Kyle Guy 2 |
Seventh Woods 1 | Blocks | De'Andre Hunter 1 |
Team | Points | FG% | 3PM-3PA | FTM-FTA | Assists | Rebounds | Blocks | Steals | Turnovers |
North Carolina | 63 | 40.8 | 10-25 | 13-17 | 15 | 29 | 1 | 2 | 9 |
Virginia | 71 | 42.0 | 9-17 | 20-22 | 15 | 26 | 2 | 4 | 4 |