Jordan says the most recent census counted 1.265 million Syrians in the kingdom, or twice the number of registered Syrian refugees.
The preliminary figures were released ahead of next week's annual Syria aid conference.
In appealing for more international aid, Jordanian officials usually cite the total number of Syrians in the country, including those who arrived before the outbreak of the 2011 Syria conflict, often in search of work.
The United Nations has registered about 635,000 Syrian refugees in Jordan since 2011.
The census, conducted late last year, indicates that 9.5 million people live in Jordan, including 6.6 million Jordanians and 2.9 million non-citizens. The figures were published in Jordanian media and confirmed Sunday by statistics department chief Qasem al-Zoubi.
Syrians make up the largest group of foreigners.