Wearing the white terrycloth garment symbolic of the Muslim pilgrimage, a maximum of 6,000 people a day will now be allowed to enter the sprawling Grand Mosque in Mecca.
The kingdom took the rare step in March of suspending the smaller "umrah" pilgrimage as the global coronavirus pandemic took hold.
The occasion draws millions from across the world all year round.
Only Saudi citizens and residents will be permitted to enter the mosque during its first phase of reopening - each person has up to three hours to complete the pilgrimage.
The Grand Mosque, which is being sterilised and cleaned multiple times a day, houses the cube-shaped Kaaba.
Before visitors can enter the mosque to pray or perform the umrah, they have to apply and reserve a specific time and date through an online application to avoid crowding and maintain social distancing.
Visitors can also select via the app their means of transportation and meeting points.
State TV on Sunday showed what appeared to be fewer than 50 people circling the Kaaba at the same time and walking several metres apart.
Typically, the mosque would be packed with worshippers from around the world crowded shoulder to shoulder at all times of the day and night.
The second phase for loosening restrictions at the Grand Mosque comes into effect on October 18.
Muslim travellers from outside Saudi Arabia could be allowed to perform the umrah pilgrimage as early as November 1, the Interior Ministry has said.