“I've been closely following JHR's ascension in the past few seasons,” said Grosjean.
“The team has showcased significant growth, and I am eager to contribute my experience as we aim for a strong 2024 season.”
Team Principal Ricardo Juncos remarked, “Romain Grosjean brings an unparalleled pedigree in motorsports.
“His leadership and experience are precisely what we need to propel JHR to new heights in the NTT IndyCar Series.”
Brad Hollinger, JHR co-owner, added, “Romain Grosjean has a history of competing at the pinnacle of motorsports.
“His expertise will be invaluable as we strive to redefine our performance metrics, both on and off the track.”
Ilott's split from JHR was announced a week ago, while Grosjean has taken legal action against his former team, Andretti Global, over an alleged breach of contract.
The latter twice qualified on pole position and twice finished in second place in the first four races of the 2023 IndyCar Series but would ultimately end the season 13th in the standings.