Mobile users in Saudi Arabia, Bahrain and Kuwait can now access the service without triggering data charges thanks to a deal between the Wikimedia Foundation and Saudi Telecom (STC).
The initiative was launched as part of the Wikipedia Zero programme, a scheme to bring the online encyclopaedia to developing countries at no cost.
"We are thrilled that STC has joined us in removing a major barrier to accessing Wikipedia on mobile phones," said Wikimedia head Kul Takanao Wadhwa.
"Improving access to the Wikimedia projects in the Arabic speaking world is a strategic priority for the Foundation, and this partnership is a step forward in our mission to enable everyone on the planet to access free knowledge."
STC subscribers can access the service in both English and Arabic. A text-only version has also been rolled out for users with slow connection speeds.