In all the world, สมพันธุ์ (สมพันธุ์ 
) is a very rare mostly boy's, but seldom female first name. The first name สมพันธุ์ is characteristic of South-eastern Asia, particularly Thailand, where it is a very rare mostly boy's, but seldom girly name. Likewise, สมพันธุ์ is the last name as well as the forename.