In 1912 he married actress Emmy Reye, but the marriage only lasted a short while. In 1921 he married Hilda Pangust and in 1957 he married Maria Pierenkämper. Rowohlt had two sons, both illegitimate: Heinrich Maria Ledig-Rowohlt (1908–1992), who succeeded him as head of the publishing house, and Harry Rowohlt (1945-2015), a writer. He also had one daughter.
With the rise of the Nazis he switched to safer non-fiction and travel works, and in 1937 joined the Nazi party. He insisted on keeping his Jewish staff and editors and remained publisher for officially disapproved writers such as Hans Fallada. In 1936 he allowed Jewish author Bruno Adler to publish a biography of Adalbert Stifter under a pseudonym. When discovered in 1938, he was banned by the Nazis from working as a publisher.
Rowolt handed control of the firm to his son Heinrich Maria Ledig-Rowohlt and fled to Brazil, but he returned to Germany during the war and became a Captain in the Wehrmacht on the eastern front until his politically motivated discharge in 1943.
- Hans Fallada (20 January 2015). A Stranger in My Own Country: The 1944 Prison Diary. Wiley. pp. 255–. ISBN 978-0-7456-8154-2.
- Shareen Blair Brysac (23 May 2002). Resisting Hitler: Mildred Harnack and the Red Orchestra. Oxford University Press. pp. 358–. ISBN 978-0-19-992388-5.
- Jan-Pieter Barbian (29 August 2013). The Politics of Literature in Nazi Germany: Books in the Media Dictatorship. Bloomsbury Publishing. p. 182. ISBN 978-1-4411-6814-6.CS1 maint: multiple names: authors list (link)