Saudi state TV said on Tuesday that the kingdom had officially begun its membership of the BRICS bloc.
Saudi Arabia's foreign minister had said in August that the kingdom would study the details before the proposed Jan. 1 joining date and take "the appropriate decision."
Prince Faisal bin Farhan had said BRICS was "a beneficial and important channel" to strengthen economic cooperation.
BRICS is an intergovernmental organization comprising Brazil, Russia, India, China, South Africa, Egypt, Ethiopia, Iran, Saudi Arabia and the United Arab Emirates.