Monday's move ratchets up pressure on Egypt as it implements austerity measures in the hope of securing billions of dollars in loans to stabilise its moribund economy.
Egyptian Oil Ministry spokesman Hamdi Abdel-Aziz said Saudi Arabia's Aramco, the world's largest oil company, stopped sending the fuel shipments to Egypt "without giving a specific timetable or reasons".
Saudi Arabia agreed in April to provide Egypt with 700,000 tonnes of fuel monthly for five years on easy repayment terms, but Egypt said last month that October's shipment had been halted.
The Saudi government has not spoken about the matter, and Aramco did not immediately respond to a request for comment.
The move appears to have been taken in response to Egypt's support of a UN Security Council resolution on Syria that was fiercely opposed by Riyadh.
Saudi Arabia is a leading supporter of the rebels fighting to topple Syrian President Bashar al-Assad. Egypt, on the other hand, has pushed for a political solution that might keep him in power.
Saudi Arabia provided billions of dollars in aid to Egypt after the military-led overthrow of then-president Mohamed Morsi in 2013. But that support appears to have dried up, forcing Cairo to court other patrons.