Leonora Marescoe, née Lethiulliers (1637-1715) was an English merchant. She belonged to the more noted members of the merchant class in Restoration period London. She managed the trading company Marescoe-Joyes from 1670 until 1675.
Leonora Marescoe was the daughter of a successful merchant and belonged to a London colony of Huguenots from the Spanish Netherlands. She married in 1658 to Charles Marescoe, with the same background and who were one of the most successful merchants in London during the 1660s. After the death of her spouse in 1670, the took over the company. The Marescoe-Joyes belonged to the greatest elite trading houses in London. One of its main trades were that of copper with contacts in the Baltic Sea and , were one of her most noted business partners were Debora van der Plas. In 1675, she married the former student of her spouse, Jacob David.