Cognomen Ы (Ы 
) , all over the world, is a very rare family name. The cognomen Ы is characteristic of Kyrgyzstan, where it is a very rare surname, Kazakhstan, and Russia, where it is an extremely rare surname. Measured by absolute frequency, it is the most numerous in China, Russia, and Kyrgyzstan. Also, Ы is the forename as well as the last name.