kathait(Devnagari:कठैत) is a surname which is prevalently found in Garhwal Region of Uttarakhand state country India. So, basically Kathait is a Kshatriya Rajput surname who served as nobles, ministers and bureaucrats under the Garhwal Kingdom.
Kathait families in Uttarakhand were chiefly Thokdars/Faujdars(Zamindars) who held the land grant from the King of Garhwal . The term "Kathait" Originally came from Katoch Rajput who are said to be their Ascendent(Ancestors). Kathait belong to Kshatriya Varna and they were katoch Rajput from Chandravanshi Rajput clan who migrated from Kangra,Himachal Pradesh to Garhwal,Uttarakhand.