Kaja or Kája is a given name and surname.
Kaja also has several root name derivations. In Polish, it is a feminine given name that is a diminutive form of Karolina, a derivative of Karl .[1] Kája is a Czech unisex given name that is a diminutive form of Karolína, Karla and Karel, also derivatives of Karl.[2] In Slovene, Kaja is often a diminutive form of Kajetana, Karla and Katarina, names deriving from Caietanus (Cajetan), Karl and Aikaterine, respectively.[3] It is also a Danish, Finnish, German, Norwegian and Swedish feminine given name that is a diminutive form of Katherina, Karen and Katrine as well as an alternate form of Kaia, all derived from Aikaterine.[4] In Estonian, Kaja is a form of Katariina,[5] but it also means "echo".[6] Notable people referred to by this name include the following: