Dietrich (Dieter) Paul Mahlow (* 19. August 1920 in Seehausen; † 11. Juni 2013 in Darmstadt) war ein deutscher Ausstellungsmacher, Kurator und Museumsdirektor. Er war damals in seiner interdisziplinären, thematischen und internationalen Arbeit ein Vorreiter und Pionier dessen, was heute den Beruf freier Ausstellungskuratoren, oder “curators” im Englischen, ausmacht. Seine beruflichen Anfänge waren in den 1950er bis in die 1970er Jahre hinein als Museumsdirektor der Staatlichen Kunsthalle Baden-Baden und Kunsthalle Nürnberg, danach arbeitete er als freier Ausstellungsmacher, Dozent und projektbezogen international in Europa und Südamerika.
Dietrich Mahlow was a curator and museum director strongly dedicated to concrete art, op art and related movements in the fine arts of the second half of the XXth century. With his interdisciplinary and international approach to design and realize exhibitions, often as a freelancer, he became one of those who paved the way for what became known as the new curator.

He became director of Kunsthalle Baden-Baden (Germany) in 1956 after finishing his doctoral dissertation in art history (Die Kunst in der Ästhetik. Die Kunst bei G.W. Leibniz und in der Ästhetik A.G. Baumgartens. University of Freiburg 1955). Mahlow stayed in Baden-Baden until 1967 during which time he made the museum a successful showcase of the cultures of the world.

He left Baden-Baden to become founding director of Kunsthalle Nuremberg (Germany) in 1967. The city of Nuremberg had decided to start a collection of art for which Mahlow developed a concept and the plan for a new museum that should in 30 rooms provide space for 30 artists. Each artist would have his or her dedicated room that they should arrange themselves if possible. When the decision was taken to discontinue the planning of the new museum in 1971, Mahlow left.

During the short years in Nuremberg, he had started a Nuremberg Biennale that took place twice (in 1969 and 1971). Both shows were dedicated to concrete art. The 1969 exhibition included work by Georg Nees.

Several times Mahlow was a member of the committee for the Venice Biennale. In 1970, he there organized a special show under the title Proposal for an Experimental Exhibition. It united Russian constructivist art, concrete art, computer art, and op art.