Combattants MMA — MMA Vlaardingen

Dutch mixed martial artist (born 1992)

Costello van Steenis is a Dutch-Spanish professional mixed martial artist who currently competes in the middleweight division of the PFL, where he is the current and inaugural PFL Middleweight World Champion. Van Steenis has been a professional MMA fighter since 2014 and has previously competed in Bellator MMA. As of January 27, 2026, he is #4 in the PFL men's pound-for-pound rankings.