Family name ウダイ (Uday 
, Oday 
, Udai 
) , around the world, is a common surname. The surname ウダイ is habitual in Israel, where it is quite a rare surname, Iraq, and Nepal. Measured by absolute frequency, it is the most numerous in India, Japan, and the United States. Much more prevalently, ウダイ is the forename as well as the last name.