A tourist with the British and Irish Lions in 2021, Van der Merwe is in his second spell with Edinburgh having returned in 2022 following the collapse of Worcester Warriors, where he spent two years.
He has scored 45 tries in 98 appearances for Edinburgh having initially signed from Montpellier in 2017.
“This club and city are my home,” Van der Merwe said. “My wife and I love it here and I’m incredibly proud to represent the city and our supporters.
“I’d be lying if I said other clubs didn’t express interest, but Edinburgh is home for me, and my connection to the club and our supporters were a massive driver in my decision to re-sign.”
