The Dutchman previously spent four seasons with Envision between 2018-2022, during which time he took two wins and secured a best result of fourth in the drivers’ standings during the 2018-2019 campaign.
Frijns moved to Abt Cupra this year but endured a miserable season, breaking his wrist in the opening round and as a result missed four races.
On his return to racing, he only finished in the points on two occasions, with the highlight of the season being a surprise pole position in the wet in Berlin.
“I’m really excited about getting started again with Envision Racing after a year away from the team, it really does feel like coming home,” said Frijns, who earlier this month was confirmed as a BMW works drivers ahead of the marque’s return to the World Endurance Championship.
“It will be great to be joining a championship-winning team. Envision Racing have been fighting at the top pretty much every season, and I can’t wait to get started.
“We have a great car, and the aim is to be competitive, which I am sure we will be, and I am driving to win the championship.”
Frijns replaces Cassidy, who has joined Jaguar ahead of 2024, and will partner Sebastien Buemi at Envision.
He also joins the reigning teams' champions, Envision having beaten Jaguar on the final day of the season in London after Cassidy won and Buemi finished sixth.
Sylvain Filippi, Envision managing director, said: “It is great to have Robin back with the team after one year away.
“He enjoyed some memorable moments with Envision over the years and was always pushing at the front and regularly fishing on the podium. The combination of Robin and Sebastien will be a strong one, and we can't wait to get started for Season 10.”
Envision is only the second team to formally confirm its driver line-up for the 2023-2024 season, which is due to get under way in Mexico City in January.
