Sir Matthew Decker, 1st Baronet (1679 – 18 March 1749) was an English merchant and writer on trade.
He was born in Amsterdam, came to London in 1702 and established himself there as a merchant. He was remarkably successful in his business life, gaining great wealth and having many honours conferred upon him. He was a director of the East India Company, sat in Parliament for four years as member for Bishop's Castle, and was High Sheriff of Surrey in 1729. He was created a baronet, of London, by George I in 1716. He lived at Richmond on Thames in Surrey.
He married Henrietta Watkins, daughter of the Reverend Richard Watkins of Wickford, Warwick, and had two daughters:Catherine (died 1786), who married Richard FitzWilliam, 6th Viscount FitzWilliam, and had issue
Henrietta Anne (died 1747), who married John Talbot, but had no issue.
Since he had no male heir, the title died with him: his fortune and estates passed to his surviving daughter Catherine, and then to her son Richard FitzWilliam, 7th Viscount FitzWilliam.
Decker's fame as a writer on trade rests on two tracts. The first, Serious considerations on the several high duties which the Nation in general, as well as Trade in particular, labours under, with a proposal for preventing the removal of goods, discharging the trader from any search, and raising all the Publick Supplies by one single Tax (1743; name affixed to 7th edition, 1756), proposed to do away with customs duties and substitute a tax upon houses. He also suggested taking the duty off tea and putting instead a licence duty on households wishing to consume it. The second, an Essay on the Causes of the Decline of the Foreign Trade, consequently of the value of the lands in Britain, and on the means to restore both (1744), has been attributed to W. Richardson, but internal evidence is strongly in favor of Decker's authorship. He advocates the licence plan in an extended form; urges the repeal of import duties and the abolition of bounties, and, in general, shows himself such a strong supporter of the doctrine of free trade as to rank as one of the most important thinkers in the early development of economic science.