Theodorus Wilhelmus (Theo) Maassen (born 8 December 1966 in Oegstgeest, South Holland) is a Dutch comedian and actor who grew up in the village of Zijtaart (municipality of Veghel) in the Dutch province of North Brabant.

Maassen won two of the biggest comedy contests in the Netherlands in 1990, the Groninger Studenten Cabaret Festival (GSCF), and Cameretten.

He also has released a song titled Lauwe Pis (Lukewarm Piss) which peaked at #1 on the Dutch Top 40.

Maassen once stole the UEFA cup from the stadium of football club PSV Eindhoven.

In 2008 Maassen started the organization Comedians for Congo to raise money for children fleeing the war torn country.