Smith went over the 4,000-yard mark for the second straight season and became the first West Virginia quarterback to throw for 40 touchdowns.
"I'm proud of his accomplishments," said West Virginia coach Dana Holgorsen. "He's a great kid. He'll be remembered around here for that for a long, long time."
In its debut season in the Big 12, the Mountaineers (7-5, 4-5 Big 12) finished tied for fifth place with Baylor, TCU and Texas Tech.
Now all that's left is for West Virginia to find out Sunday where it will play in a bowl for the 11th straight season.
Biletnikoff Award finalist Stedman Bailey had 159 receiving yards and two touchdown grabs to boost his Bowl Subdivision leading total to 23.
Andrew Buie, who rushed for 100 yards, had a 42-yard reception on a screen play set up Bailey's second touchdown, an 18 yarder that put the Mountaineers ahead 45-7 midway through the third quarter.
Weis hoped to use a bye week to try to figure out a way to slow down Austin, but the Jayhawks had little luck.
Austin set up three first-half touchdowns with long plays. He had four catches for 110 yards, 77 rushing yards and a score and broke his own single-season school record for all-purpose yards.
Austin has 2,760 total yards this season, second in the FBS to Western Kentucky's Antonio Andrews (2,977).
West Virginia surpassed 200 rushing yards for the third straight week since Austin was inserted into the backfield as well as playing his slot receiver spot. In the three games before that, the Mountaineers failed to reach 100 yards on the ground.
"When we get the ground game going, that alleviates the pressure for (Smith)," Holgorsen said. "Us being able to run the ball makes his stats look a whole lot better."