One of the five pillars of Islam, the hajj must be undertaken by all Muslims who have the means at least once in their lives.
Usually one of the world's largest religious gatherings, about 2.5 million people participated in 2019.
But after the onset of the pandemic in 2020, Saudi authorities announced they would only let 1,000 pilgrims take part.
The following year, they increased the total to 60,000 fully vaccinated Saudi citizens and residents chosen through a lottery.
Barring overseas pilgrims caused deep disappointment among Muslims worldwide, who typically save for years to take part.
In April, the kingdom announced it would permit one million Muslims from inside and outside the country to participate in this year's hajj, which will take place in July.
The hajj consists of a series of religious rites that are completed over five days in Islam's holiest city, Mecca, and surrounding areas of western Saudi Arabia.
Hosting the hajj is a matter of prestige for Saudi rulers, as the custodianship of Islam's holiest sites is the most powerful source of their political legitimacy.
Before the pandemic, Muslim pilgrimages were major revenue earners for the kingdom, bringing in about $12 billion annually.
This year's pilgrimage will be limited to vaccinated Muslims under age 65, the hajj ministry has said.
Those coming from outside Saudi Arabia, who must apply for hajj visas, are required to submit a negative Covid-19 PCR result from a test taken within 72 hours of travel.