Hans Winthrop Mortimer of Caldwell Hall, Derbyshire (May 3, 1734 – February 26, 1807) was a British property speculator and politician who sat in the House of Commons between 1775 and 1790. The only son of Cromwell Mortimer of Topping Hall, Essex, he succeeded to his father’s estates in 1752, entering Lincoln’s Inn in 1755 and was called to the bar in 1761. Sometime before 1768, he sold Topping Hall and bought and started developing an area of farmland known as Brickfields in the north west corner of Bloomsbury, London. He built Mortimer Market as a food and general market. It appears partially developed on Horwood’s plan of 1799. In 1825, by now in financial straits, Mortimer sold the eastern part of the estate to John Smith, Benjamin Shaw, and Isaac Lyon Goldsmid, founders of the new University of London (now UCL). According to parliamentary historian and political reformer, Thomas Oldfield, writing in 1816, Mortimer was confined for some years as a prisoner for debt in Fleet prison. The street was bombed during World War Two and subsequently redeveloped by UCL and UCH.