Sergiu Dan (Romanian pronunciation: [ˈserd͡ʒju dan]; born Isidor Rotman or Rottman; December 29, 1903 – March 13, 1976) was a Romanian novelist, journalist, Holocaust survivor and political prisoner of the communist regime. Dan, the friend and collaborator of Romulus Dianu, was noted during the interwar period as a contributor to Romania's avant-garde and modernist scene, collaborating with poet Ion Vinea on Contimporanul review and Facla newspaper. He was also affiliated with the rival literary club, Sburătorul, and noted for criticizing the communist sympathies of other avant-garde writers. His main works of the 1930s include contributions to the psychological novel, thriller and political novel genres, received with critical acclaim.
Of Jewish Romanian origin, Sergiu Dan was the subject of antisemitic defamation, and, during World War II, was deported to Transnistria. After his return home, Dan spoke about his experiences in the book Unde începe noaptea ("Where Night Begins"), which endures one of the few Romanian contributions to Holocaust literature, and has for long been censored by dictatorial regimes. The writer's political stance also clashed with the post-1948 communist establishment, and, during the 1950s, he was interned at Aiud prison. Dan was eventually forced to adapt his writing style to the aesthetic requirements of Romanian Socialist realism, and spent the final decades of his life in relative obscurity. His work was rediscovered and reassessed following the 1989 Revolution.