Heinsius is a surname of Dutch and German origin. Notable people with that surname include:
Anthonie Heinsius (1641-1720), Dutch statesmanDaniel Heinsius (1580-1655), Dutch scholar and poetGottfried Heinsius (1709-69), German mathematician, geographer and astronomerJohann Julius Heinsius (1740-1812), German oil painter and miniaturistJohann Samuel Heinsius (1686–1750), German bookseller and publisherNicolaas Heinsius the Elder (1620–81), Dutch scholar and poet, son of Daniel HeinsiusNicolaas Heinsius the Younger (1655–1718), Dutch physician and writer, son of Nikolaas the Elder