Cognomen Ryby (Ryby 
, Рыбий 
) , all around the world, is a rare last name. The family name Ryby is characteristic of Denmark, where it is a rare surname, Belarus, where it is a very rare surname, and Kazakhstan. Measured by absolute frequency, the name is most common in Russia, Denmark, and Kazakhstan. Much less frequently, Ryby is the forename as well as the last name.