Charles Lahr (1885–1971), born Carl Lahr, was a German-born anarchist, London bookseller and publisher.
Lahr was born at Bad Nauheim in the Rhineland, the eldest of 15 children in a farming family. He left Germany in 1905 to avoid military service and went to England.
In London he encountered the anarchist Guy Aldred (1886–1963), while working as a baker. He was soon (1907) under police observation. He joined the Industrial Workers of the World in 1914; at that time he had a bookshop in Hammersmith.
In 1915 he was interned for four year as an enemy alien in Alexandra Palace. In 1920-21 he was briefly a member of the Communist Party of Great Britain. His interest in politics led him to befriend many left-wing thinkers, several of whom went on to establish important left-wing groups in the UK. In 1921 he took over the Progressive Bookshop, in Red Lion Street, Holborn. From there he would branch out into publishing, and establish many literary friendships (including H. E. Bates, Rhys Davies, T. F. Powys) and D. H. Lawrence. At one point when Lahr was in financial difficulties his writer friends gathered a collection of stories together and published these as Charles Wain (1933).
He married in 1922 Esther Argeband, (at that time Archer), whom he had met at the Charlotte Street Socialist Club, of a British Jewish family (Lahr was not Jewish). They were close friends of William Roberts, the artist, and his wife, and William's portrait of Esther is in the Tate Gallery.