* As a Danish and Norwegian surname, from various places derived from Old Norse borg (“stronghold”).
* As a north/Low German surname, this is the Low German form of the surname Burg.
* As a Jewish surname, from Yiddish בורג (burg, “credit”), from Middle High German borgen (“to lend, borrow”), from Old High German borgēn.
* As a Maltese surname, from the noun borġ (“tower, stronghold”), distantly related to the first two senses above.