The Razorbacks (25-8) won their third straight to reach the championship for the seventh time. They will play No. 1 seed Kentucky, a 79-74 winner over Alabama, for the second time in three years Sunday.
Arkansas simply smothered Vanderbilt, especially in the paint where the Razorbacks had a 46-16 scoring edge.
Playing a third game in as many days took its toll on seventh-seeded Vanderbilt (19-15). The Commodores saw a three-game winning streak end after reaching the semifinals for the first time since 2013.
These teams won on each other's floor during the season with Vandy a blown 15-point lead away from sweeping Arkansas.
This time, the Razorbacks led 35-31 at halftime and took control with a 21-4 run to start the second half.
Vandy coach Bryce Drew tried to rest his starters where he could in the first half with Luke Kornet and Roberson playing only 12 minutes after each played at least 38 minutes in Friday's overtime win over No. 17 Florida in the quarterfinals. It just wasn't enough as the Commodores missed their first nine shots to start the game and the first six of the second.
Vandy used a 12-2 run to take its first lead but couldn't hold it for long.
Barford scored seven of his 10 points in a quick spurt after a tie at 19 to put the Razorbacks ahead to stay.
Arkansas, outscored only three times in the second half all season, wound up leading by as much as 27. Vanderbilt used a 13-0 run late to make the final margin more respectable.
The Razorbacks face No. 1 seed Kentucky in Sunday's championship game at 1 p.m. ET on ESPN.