The former Lotus and Haas Formula 1 driver made his debut in the American series earlier this year for Dale Coyne Racing.

The Frenchman has enjoyed a successful rookie season, finishing on the podium on three occasions, including a third-place finish last time out at Laguna Seca.

Andretti also confirmed that Grosjean will take over the number 28 car which Ryan Hunter-Reay will vacate at the end of the season.

Grosjean will team up with Colton Herta, Alexander Rossi and an unnamed fourth driver for the 2022 campaign.

Reflecting on the announcement, he said: “I’m delighted to be joining Andretti Autosport and driving the No. 28 DHL Honda for next season. It’s a big honor to be joining such a great team as Andretti – anyone in the motorsport world knows the name Andretti.

“I’m super happy and proud to be racing with the team. I’m hoping that we are going to be very successful together, which is our aim on every side. I would like also to thank Dale Coyne Racing for giving me the opportunity to join IndyCar. I’ve enjoyed the racing so much and it’s given me the chance today to be racing with one of the most competitive and best teams in the world.”

CEO Michael Andretti was impressed with Grosjean’s CV before entering IndyCar and is confident that the 35-year-old’s “vast experience” will benefit the team.

“We are thrilled to welcome Romain to the Andretti Autosport family,” he added. “He already had an impressive resume before coming to IndyCar, and watching what he’s been able to do in his rookie season here has been exciting to say the least.

“His vast motorsport experience will be beneficial to the team alongside our already-strong 2022 driver lineup.”

Grosjean will be in action again this weekend as the IndyCar season concludes at Long Beach.