Thomas Assheton Smith (the younger) (2 August 1776 – 9 September 1858) was an English landowner and all-round sportsman who was notable for being one of the outstanding amateur cricketers of the early 19th century. He was a Tory politician who sat in the House of Commons from 1821 to 1837. He was also known for his pioneering work on the design of steam yachts in conjunction with the Scottish marine engineer Robert Napier.

A steam yacht is a class of luxury or commercial yacht with primary or secondary steam propulsion in addition to the sails usually carried by yachts.