John Blankenstein (born February 12, 1949 in De Bilt – died August 25, 2006 in The Hague) was a Dutch soccer referee. He was notable for being one of the first homosexual athletes to come out in the Netherlands. After playing as an amateur player, he refereed games from 1966 to 1995, and participated on the highest FIFA level. Highlights of his career were the UEFA Cup final in 1993 and being chosen for the 1992 European Championship.