Boris Ottokar Dittrich (Dutch pronunciation: [ˈboːrɪz ˈditrix]) is a human rights activist and a former Dutch politician and writer.
Dittrich's father came to the Netherlands as a political asylum seeker from Czechoslovakia in 1948, he became a professor in Eastern-European history at the University of Utrecht.

Boris Dittrich grew up in Utrecht and went to law school at Leiden University. He worked as a lawyer in Amsterdam from 1981 till 1989 and later as a judge in the district court of Alkmaar from 1989 till 1994. Dittrich is married to the Dutch / Israeli sculptor Jehoshua Rozenman.

In 1994 Dittrich became a member of parliament representing the social-liberal party D66.

Boris Dittrich rose to become party leader of D66 in 2003.

In early 2007 Dittrich became Advocacy Director of the Lesbian, Gay, Bisexual & Transgender (LGBT) Rights Program at Human Rights Watch in the Headquarters of the non-governmental organization in New York City.

Mid 2013 Dittrich moved from New York to Berlin, Germany where he continues to work as global advocacy director of the LGBT Rights Program at Human Rights Watch.