Jacob Israël de Haan (31 December 1881 – 30 June 1924) was a Dutch Jewish literary writer and journalist who was assassinated in Jerusalem by the Jewish paramilitary organization Haganah for his anti-Zionist political activities and contacts with Arab leaders.
De Haan was born in the Netherlands, in Smilde, a village in the northern province of Drenthe, and grew up in Zaandam. He was one of eighteen children and received a traditional Jewish education. His father, Yitzchak HaLevi de Haan, was poor and worked as a hazzan and Shochet. His sister, best known under her married name Carry van Bruggen (née, Caroline Lea de Haan), became an important Dutch author.
De Haan worked as a teacher and studied law between 1903 and 1909. He wrote in socialist publications and various other magazines during these years. He was a friend of Frederik van Eeden and Arnold Aletrino, Dutch authors of the Tachtiger school.
In 1904, while living in Amsterdam, he wrote his controversial novel Pijpelijntjes ("Lines from De Pijp"), which pretends to be a thinly veiled version of his own gay life with Aletrino in Amsterdam's "Pijp" working-class district. The homo-eroticism of the book, shocking in the early 20th century, led to his dismissal from his teaching job and social-democratic political circles. Aletrino and Johanna van Maarseveen, de Haan's fiancée, bought almost the entire print run of the book, to keep a lid on the scandal.
In 1907 he married van Maarseveen, a non-Jewish doctor, but this marriage is likely to have been platonic; they separated in 1919 but never officially divorced. A second controversial novel, Pathologieën (1908, "Pathologies") described the sorrows and joys of a sadomasochist relationship. However, this book went largely unnoticed, as did De Haan's prose sketches. He published five volumes of poems between 1914 and 1921 that brought him some acclaim.