Last name 惟一 (Weiyi 
, 惟一 ) , across the world, is a rare cognomen. The family name 惟一 is characteristic of Taiwan, where it is quite a rare surname, Singapore, 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 China, Taiwan, and Singapore. Predominantly, 惟一 is the forename as well as the last name.