Last name Gelii (Гелий 
, Gelii 
) , globally, is a very rare cognomen. The family name Gelii is characteristic of Belarus, where it is a rare surname, Kyrgyzstan, where it is a very rare surname, and Ukraine. Measured by absolute frequency, it is commonest in Eastern Europe, particularly Belarus, Ukraine, and Russia. Predominantly, Gelii is the forename as well as the last name.