The experienced second-row boasts a wealth of experience at the highest level of the game, representing both Ireland (residency) and South Africa (birth) at international level.
Kleyn won the 2023 World Cup with the Springboks and enjoyed URC success with Munster during Graham Rowntree's reign and will be a welcome new arrival at Gloucester.
Renowned for his physicality, work-rate, and leadership, the 6'8" 32-year-old second-row is set to offer significant quality and depth to the Gloucester pack from next season.
Speaking on the move, Kleyn added: “I'm thrilled to be joining Gloucester Rugby next season. It's a club with incredible history and a passionate fan base, and the vision shared with me really matched what I was looking for in the next chapter of my career.
“I can't wait to get started, meet the supporters, and give everything I have for this team.”
Kleyn will link up with the Cherry and Whites at the end of the URC, as preparations begin for the 2026/2027 season.
Kleyn is currently in his 10th season at Munster and made 160 appearances for the Limerick outfit.
The Sharks have confirmed the signings of former Harlequins lock Stephan Lewies and Perpignan front-row forward Nemo Roelofse, with both players set to join the Durban-based side ahead of the 2026/27 season.
Springbok prop Ox Nche says the Sharks are treating their Champions Cup match against Clermont as if it were a playoff game and want to get the maximum points available from the fixture.
Springbok eighth man Jasper Wiese put in a superb all-action display in the Urayasu D-Rocks' 28-22 win over Jesse Kriel's Yokohama Canon Eagles.
The final match in the highly anticipated Rugby's Greatest Rivalry series between South Africa and New Zealand could take place in the United States of America, according to reports.
