Surname บุญธรรม (บุญธรรม 
, Boontham 
, Buntham 
, among others...) , in all the world, is a common cognomen. The cognomen บุญธรรม is habitual in Thailand, where it is quite a common surname, Sweden, where it is a rare surname, and Malaysia, where it is a very rare surname. Measured by absolute frequency, this name is the most popular in Thailand, the United States, and Sweden. Also, บุญธรรม is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| บุญธรรม | Thailand |
| Boontham | Sweden, China, United States, Australia, Thailand |
| Buntham | United States, Malaysia, Thailand |
| Boonthum | United States, New Zealand, Thailand |
| Boontam | United States, United Kingdom, Hungary, Thailand |
Amboontham, Aunboontum, Bhoontham, Bhundhumanee, Boobthamma, Boonaom, Boondham, Boondharm, Boondhum, Boonham, Boonkhamma, Boonmaeng, Boonthaing, Boonthair, Boonthakham, Boonthakum, Boonthaman, Boonthamee, Boonthamm, Boonthamma, Boonthammarat, Boonthammee, Boonthammit, Boontharm, Boontharvee, Boonthaum, Boontheam, Boontheing, Boonthit, Boonthoom, Boonthorm, Boontom, Boontumth, Booontum, Boorntham, Bumpentham, Bunatham, Bundithum, Bunmaeng, Buntam, Buntamsong, Bunthaem, Bunthamma, Bunthanm, Buntharm, Bunthurm, Buntthaem, Maboontham, Makboontham, Oonboontham, and Unboontham