Tekori, 35, made 37 appearances since his debut in 2007 scoring five tries and featured at the tournament on three previous occasions.
“It was not an easy decision to make but I am blessed and grateful to have been able to put on the blue jersey and play to represent my beautiful country Samoa,” he posted on Instagram.
“My time has come and to now focus my rugby career on the club I am playing for now,” he added.
The powerful back-rower won the second French Top 14 of his career with Toulouse in July adding to his title with Castres in 2013.
Tekori joins fellow Pacific islanders in former Fiji wingers Nemani Nadolo and Timoci Nagusa in hanging up their boots this year.
Samoa face Russia, Scotland, Ireland and hosts Japan in the group stages at the competition which begins on September 20.