Saracens have secured the services of Schalk Burger on a two-year deal, which will come into force at the start of the 2016-17 campaign.
The former World Rugby Player of the Year will join Sarries after spells with Japanese club Suntory Sungoliath and Super Rugby's Stormers in his native South Africa.
"I'm delighted to be joining Saracens. I'm extremely excited to have the opportunity to play in both the Aviva Premiership and the European Cup, two of the leading competitions in world rugby for such a special club," the 32-year-old told the club's official website.
"It's an exciting challenge for me and my family and hopefully I can add a lot of value both on and off the field to an already successful group of players and coaches.
"I'm looking forward to playing alongside my new teammates and playing in front of all the Saracens fans and getting to know everyone at Allianz Park."
Burger announced his retirement from international rugby following the conclusion of the most recent Rugby World Cup.
