Last name Semis (Semis 
) , in all the world, is a rare surname. The cognomen Semis is characteristic of Lithuania, where it is quite a rare surname, Spain, where it is a rare surname, and Malaysia, where it is a very rare surname. Measured by absolute frequency, the name is most common in Spain, France, and Lithuania. Much less frequently, Semis is the forename as well as the last name.