Johann-Friedrich Betgen (1721? - 1738) was a surveyor and mapmaker, whose name survives in connection with a single work: the Homann Heirs map of Lithuania Minor. If the dates for Betgen are correct, his 1733 contribution to that map was done at the tender age of twelve. It seems likely that his role was circumscribed to the plan of Gusev which appeared on the broader map: a work so professional and detailed that to credit it to a child beggars the imagination. Nothing is known of Betgen's life and training, although his family name suggests a Dutch background.