William Heinemann was a publisher. He was the eldest son of Louis Heinemann of Hanover, who became naturalized in 1856, and his wife, Jane Lavino, from Manchester. Heinemann married Magda Stuart Sindici, an Italian novelist, in February 1899; they were divorced in 1904. His brother Edmund was a financier.
After a cosmopolitan education in both Dresden and London, Heinemann trained in the publishing industry at Messrs Trübner. He set up his own business in 1890, and his association with Whistler began in June of that year, with the publication of The Gentle Art of Making Enemies. In 1892 Whistler attempted to get some of Mallarmé's address quatrains published by Heinemann (see GUW #08025). Also in that year, Whistler was planning with Heinemann to publish a set of lithographs entitled 'Songs on Stone', which they hoped would be popular and profitable. Heinemann also was a collector and bought lithographs by Whistler from the Fine Art Society in 1895.
After Beatrice Whistler's death in 1896, Whistler made his home with Heinemann at 4 Whitehall Court for a while. In 1899, Whistler congratulated Heineman on his engagement to 'the most fair and dainty Donna!' (GUW #08514) and in February that year Whistler was best man at the wedding in Porto d'Anzio in Italy. Whistler designed monograms for the Heinemanns which were used on their notepaper (Designs for monograms for William and Magda Heinemann m1534). The Heinemanns were extremely hospitable and in 1900 Whistler stayed with them at Norfolk Street, Mayfair on several occasions. In October of that year he painted a portrait of Mrs Heinemann (Portrait of Mrs William Heinemann y531).
In Whistler's later years, Heinemann sometimes travelled with Whistler. Keen to see his friend properly memorialised, after 'years of badgering', Heinemann proposed W. E. Henley and Charles Whibley to write Whistler's biography, Whistler objected to both. He then asked the Pennells, and subsequently published their work, Pennell, Elizabeth Robins, and Joseph Pennell, The Life of James McNeill Whistler, 2 vols, London and Philadelphia, 1908 .
Heinemann was President of the Publishers' Association of Great Britain and Ireland, 1909–1911 and President of the National Booksellers' Provident Society, 1913–1920. When he died suddenly in 1920 he was living at 32 Lower Belgrave Street, London. His sale was held at the AAA, New York on 13 January 1922.
Spink, Nesta R., Harriet K. Stratis, and Martha Tedeschi, The Lithographs of James McNeill Whistler, (gen. eds, Harriet K. Stratis and Martha Tedeschi), 2 vols., Chicago, 1998 , p. 175; St John, John, William Heinemann: a century of publishing 1890-1990, London, 1990; Whyte, Frederic, William Heinemann: A Memoir, London, 1928; Dictionary of National Biography, Oxford, on-line edition. The Correspondence of James McNeill Whistler, 1855-1903, edited by Margaret F. MacDonald, Patricia de Montfort and Nigel Thorp; including The Correspondence of Anna McNeill Whistler, 1855-1880, edited by Georgia Toutziari. Online edition, University of Glasgow, 2004.