Cornelis Huig Jan "Jan-Cor" van der Greef (born 6 April 1983 in Vianen) is a Dutch sport shooter.
He has competed for the Netherlands at the 2004 Summer Olympics, and also established a junior world record for a fifth-place finish at the 2003 European Championships in Brno, Czech Republic.
Van der Greef is a member of Snip Shooting Club (Dutch: Schietvereniging de Snip) and a resident athlete of the Royal Netherlands Shooting Federation (Dutch: Koninklijke Nederlandse Schietsport Associatie, KNSA), where he trains under head coach Nelia Heemskerk.Van der Greef qualified for the Dutch shooting team, as a 21-year-old, in the men's skeet at the 2004 Summer Olympics in Athens.
He had registered a minimum qualifying score of 123 to join with his fellow shooter and then incoming five-time Olympian Hennie Dompeling, and fill in the second Olympic quota for the Netherlands from his fiery fifth-place finish at the European Championships a year earlier.
A newcomer to the international competition, Van der Greef shot 115 targets out of a possible 125 in the qualifying round to force a three-way tie with Great Britain's Richard Brickell and Egypt's Amr El-Gaiar for thirty-fourth place from an immense field of forty-one shooters.