The World Trade Organization (WTO) has approved Saudi Arabia's application for membership after 12 years of talks.
Saudi Arabia must open its long protected economy
The world's largest oil exporter will become the 149th member of the WTO in 30 days' time.
The country will need to adopt the entire body of WTO legislation, a process that involves liberalisation of currently restricted sectors.
Saudi Arabia must open its long protected economy to the outside world, including fellow WTO member Israel.
Saudi Arabia's participation in the Arab League boycott of Israel will thus need to be reviewed.
Some elements of the country's Islamic religious establishment have expressed concern about the WTO membership.
But Saudi Arabia's commerce and industry minister Hashim Yamani said: "This is a high point in the programme of economic and structural reform that Saudi Arabia undertook.
"The accession will further integrate Saudi Arabia's economy into the world economy. It will also deepen the universality of the multilateral trading system."
"One more heavyweight around the table is good news," agreed WTO chief Pascal Lamy.
"It's been a long process, and I firmly believe that it's good for Saudi Arabia, it's good for the trading partners of Saudi Arabia, and it's good for the organisation."
Saudi Arabia's accession to the WTO should come in time for the country's participation in December's ministerial meeting in Hong Kong, starting on 13 December.
US and European Union trade representatives have warned that a deal will almost certainly not be reached in Hong Kong after preliminary talks this week failed to make any headway.
Saudi's stock market has risen steadily since entry negotiations ended successfully on 28 October, with investors expressing high hopes about the country's economic future due to the benefits it should derive from WTO membership.
"The accession will enhance the business environment in Saudi Arabia by adding more transparency and predictability," said Mr Yamani.
"This we expect to lead to more investment and job creation."