Russia formally notified the World Trade Organization on Monday that it had ratified its membership agreement, meaning it will become the 156th member of the trade rules club on Aug 22.
The $1.9 trillion Russian economy, the world's ninth largest, was the biggest still outside the WTO.
Countries joining the body have to agree terms with all existing members and bring their laws into line with WTO rules. Once they have received the green light for membership, they must ratify their membership deal.
They have to notify the WTO that they have done so and membership follows automatically 30 days later.
Russian President Vladimir Putin signed his country's accession to the WTO into law on Saturday and a Russian diplomat handed the papers to an official at the WTO in Geneva at 2.45 pm (1245 GMT) on Monday, completing an 18-year campaign to join the club.
Other countries that are not WTO members include Iran, Iraq, Libya, Syria, Belarus, Algeria, Bosnia, Serbia, Sudan, Uzbekistan and Kazakhstan.
(Reporting by Tom Miles; Editing by Pravin Char)