The Royal Bangkok Sports Club and the RBSC Polo Club in Bangkok's Pathumwan district have been closed from May 5 until further notice, the RBSC announced on Tuesday.
The temporary closure followed a recent discovery of Covid-19 infections in communities near the clubs.
An investigation was underway into the infections and potential cases, the announcement said.
Active case finding checks on staff, instructors and caddies had so far found two RBSC staff tested positive for the virus.
The clubs apologised to members for any inconvenience, saying their safety was the highest priority.