Thailand received 9.37 million foreign visitors during the January-March period. The Southeast Asia's second largest economy had launched a series of tourism promotion policies including permanent visa waivers for China.
Malaysia, which became the regional tourism champion last year, came in second with 5.8 million arrivals, increasing by 32% year-on-year, according to data from its tourism ministry.
Vietnam was third in the region with 4.6 million, up 72% year-on-year, followed by Singapore with 4.35 million that saw a year-on-year 50% increase.
Indonesia came in fifth with 3 million foreign tourist arrivals in the first quarter.
The Philippines welcomed 1.6 million, jumping by 21.3% year-on-year while Cambodia attracted 1.58 million international tourists during the same period, up 22.5%.
Laos only welcomed 1 million foreign arrivals.
Southeast Asian countries like Thailand, Singapore and Malaysia have been racing to attract potential tourism markets such as China, India and Europe by offering visa exemption or extending visa-free stays.