Diederik Johan Mathijs "Dirk" ten Geuzendam [1] (born January 11, 1957) is a Dutch chess writer, commentator and organizer.

Ever since his meeting with American legend Bobby Fischer in Sveti Stefan in 1992, Ten Geuzendam kept a special interest in the 11th Chess World Champion.

From 2007 to 2013 he was one of the editors (together with Allard Hoogland and Rob van Vuure) of the Dutch chess literary magazine Matten.

Representing the Monaco-based Association Max Euwe of chess benefactor Joop van Oosterom, Ten Geuzendam was tournament director of the final four editions of the prestigious Amber Rapid and Blindfold Chess Tournament (2008-10 in Nice, 2011 in Monaco) and the final three editions of the NH Rising Stars vs.

Ten Geuzendam made his debut as commentary host for the English live transmission at the 2012 World Championship match between Vishy Anand and Boris Gelfand in Moscow.