Kai Maertens (* 1958) is a German actor. He began his professional career with permanent engagements in Cologne and at Hamburg’s Thalia Theater, later working on the stages of the Komödie am Kurfürstendamm in Berlin and the St. Pauli Theater in Hamburg, among others. In addition to his work as an actor, he also works as a director, for example at the Störtebeker Festival on the island of Rügen. Maertens is known to a wider audience for his numerous leading roles in film, television and radio drama productions. His brother Michael Maertens is also an actor and has read a poem by Curt Bloch.