Motorsport.com first reported Dillon was finalizing a deal with the team last week.
Bass Pro Shops and Black Rifle Coffee Company will sponsor the No. 96 Toyota as Dillon attempts to qualify for the season opener at Daytona International Speedway.
It’s the only race Dillon has announced for 2021, but he’s eligible for the Busch Clash if he can land a ride with another team.
Dillon, 28, may also run the season’s second race on the Daytona Road Course for Gaunt, but that deal remains to be determined.
“Gaunt Brothers Racing has given me a great opportunity to compete in the Daytona 500 and I couldn’t be happier,” Dillon said. “I love superspeedway races and the Daytona 500 is the biggest of them all.
“Toyota has certainly proven itself in our sport and in the Daytona 500. I’m looking forward to racing with them and reuniting with Bass Pro Shops and Black Rifle Coffee Company.”
Dillon was left without a fulltime ride in the series when the Germain Racing team with which he had competed the past four seasons shut down at the conclusion of 2020.
Dillon, the younger grandson of Richard Childress Racing Hall of Fame owner Richard Childress, won the 2011 ARCA Menards Series championship and owns three career wins in the Truck Series and one in the Xfinity Series.
In 162 Cup Series starts, Dillon’s best finish was third last fall at Talladega (Ala.) Superspeedway.
Gaunt Brothers competed as a fulltime team in the Cup Series for the first time last season with driver Daniel Suarez. Suarez will compete with the new Trackhouse Racing team in 2021.
“The best way to get a good start to your season is to have a good finish in the Daytona 500,” said Marty Gaunt, president of Gaunt Brothers Racing. “We’ve got a talented driver in Ty Dillon with a strong TRD engine plugged into the best equipment available.
“Together with Toyota, Bass Pro Shops and Black Rifle Coffee Company, we’re ready to compete and surprise some people.”