From a nickname from the Gaelic word creag ‘rock’, or in some cases a transferred use of the Scottish surname derived as a local name from this word. Though still particularly popular in Scotland, the given name is now used throughout the English-speaking world and is chosen by many people who have no connection with Scotland.
English and Scottish: patronymic from the personal name John. As an American family name, Johnson has absorbed patronymics and many other derivatives of this name in continental European languages. (For forms, see Hanks and Hodges 1988.)