Family name Киган (Keegan 
, Kigan 
, Kygan 
) , in the world, is a common last name. The cognomen Киган is habitual in Ireland, where it is quite a common surname, Australia, where it is quite a rare surname, and New Zealand. Measured by absolute frequency, the name is most common in the United States, the United Kingdom, and Ireland. Likewise, Киган is the forename as well as the last name.