Eelco Sintnicolaas (born 7 April 1987 in Dordrecht) is a Dutch track and field athlete, specialising in the decathlon.
His first result in the decathlon was a score of 8.052 points at the Götzis Meeting in 2009. That same year he earned a gold medal at the U23 European Championships, with 8.112 points, whereas his best result was a silver medal at the 2010 European Championships in Athletics in Barcelona with 8.436 points. At the Götzis Meeting in 2012 he finished second with personal best result 8506 pts.
He cleared 8000 points at the 2013 Decastar meeting, taking third place with a total of 8018.