As a boy's name this is a pet form of Jeremy or Gerald, or occasionally of Gerard and Jerome. As a girl's name it is a variant spelling of Gerry, and is sometimes bestowed as an independent given name, as in the case of the American model and actress Jerry Hall (b. 1956).
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.)