John Maberly (1770–1839) was a British businessman and Member of Parliament. John Maberly was born in London in 1770, the second child of London currier (leather finisher) Stephen Maberly and Mary (née Boot) Maberly. In 1796 he married Mary Rose Leader, the sister of William Leader, with whom he was to have six children. After originally joining his father in the family business, a large legacy in 1798 from his father-in-law enabled him to branch out on his own as a very successful military contractor, supplying uniforms to the Army. In 1811 he purchased the large Broadford linen works in Aberdeen. Around this time he also formed an alliance with steam engine pioneer Jabez Carter Hornblower, who had designed an improved steam engine. Sued by James Watt and Matthew Boulton for breach of Wat