Thorborg is a surname. Notable people with the surname include:
Helle Thorborg (born 1927), Danish painter and graphic designer Karin Thorborg (born 1948), Swedish politician Kerstin Thorborg (1896–1970), Swedish opera singer Niels Thorborg (born 1964), Danish football chairman Søren Thorborg (1889–1978), Danish gymnast
See also Torborg, a feminine given name and a surname