Jens Rostgaard, born 1650, died 1715, was a Danish soldier, civil servant, judge and antiquarian, known for leading the militia against the Swedish landing at Humlebæk in 1700, and for writing the history of Copenhagen.
From age 12 he was brought up at the home of his uncle, Hans Rostgaard, a tax collector, who had been rewarded with Krogerup Manor, for his attempt in 1659 to liberate Kronborg Castle from the Swedes during the Second Northern War.
When the Scanian War began, he returned to Denmark, and was commissioned into the Zealand Life Regiment, where he served until 1680, when his resignation was accepted.
Rostgaard then served as his old uncle's deputy, until 1684, when he succeeded him in his offices as tax collector and local administrator for Kronborg amt.
He was rewarded with the position of Rådmand (alderman) in Copenhagen, and was from 1703 war commissary and tax commissioner for Sjælland, Møn, and Lolland-Falster.