Button, who won the F1 championship with Brawn GP in 2009, will make his Cup Series debut on March 26th at COTA in Austin, Texas.
The Briton will then compete in the inaugural Chicago Street Race on July 2nd before racing at the Indianapolis Motor Speedway Road Course on August 13th. Button will drive the No. 15 Mobil 1 Ford Mustang for Rick Ware Racing.
"I won the world championship with Mobil 1, and 14 of my 15 wins in Formula 1 were with Mobil 1, as well as winning the Super GT championship with them," Button said.
"We've had a really close relationship over the years and I can't think of a better partner."
After retiring from F1 in 2017, Button drove sports cars in the Japanese Super GT Series' GT500 class, where he won the 2018 championship.
The Briton also competed in five races in the FIA World Endurance Championship that included the 24 Hours of Le Mans.
