Dirk Strider, character in the web comic "Homestuck"
Dirk Diggler, porn star character in the movie "Boogie Nights"
DirkCalloway, character in the movie "Rushmore"
DirkPitt, character in a series of novels by Clive Cussler
Dirk Mann, character in Disney Channel's "Bizaardvark"
Dirk Gently, delightfully quirky character from DouglasAdams books and TV show Dirk Gently's Holistic Detective Agency
Dirk Garthwaite aka The Wrecker, character in Marvel's Thor comics