The 28-year-old was a free agent after leaving Sekhukhune United at the end of the last campaign.
This despite the fact he was in the Bafana Bafana squad as recently as March, and had a fine 2025/26 Betway Premiership campaign.
“Kaizer Chiefs have strengthened their goalkeeping department with the signing of renowned shot-stopper Renaldo Leaner,” the club said in a statement.
“Born in Cape Town 28 years ago, Leaner arrives at Naturena with a wealth of experience, having impressed last season and earned a number of call-ups to the Bafana Bafana national team.
“We proudly welcome Renaldo to the Khosi Nation!”
Leaner joins Bruce Bvuma and Brandon Petersen as likely first team options this season, while the future of Rwanda international Fiacre Ntwari is unclear at this stage, though he has been a part of pre-season.
The keeper is the second signing for Chiefs in this transfer window after defender Thabo Moloisane also joined the club. The pair will work under new French coach Fernando Da Cruz.