David Ames Wells (June 17, 1828 – November 5, 1898) was an American engineer, textbook author, economist and advocate of low tariffs.

Wells was instrumental in abolishing the many petty taxes which had been imposed during the Civil War, and originated most of the important forms and methods of internal revenue taxation adopted from 1866 to 1870.

He started as a high-tariff supporter, but finding that high wages in America made for efficiency as compared with the backward methods of competing countries, he was converted to free trade, and became a leading advocate of abolition of the tariff.

He served as delegate to the Democratic National Conventions, and ran unsuccessfully for Congress from Connecticut in 1876 and 1890, and he made many speeches in each of Cleveland's campaigns.

He argued that industrial depressions, with falling prices, were due not to insufficient supply of money, but to sudden and rapid increase in commodities.

His writing style was characterized by simplicity, candor, and an extraordinary success in presenting statistics in a day when educated people did not understand percentages.

He wrote The Relation of the Government to the Telegraph (1873); The Cremation Theory of Specie Resumption (1875); The Silver Question (1877); Why We Trade and How We Trade (1878); Our Merchant Marine (1882); A Primer of Tariff Reform (1884); Practical Economics (1885); Recent Economic Changes (1889), a major description and analysis of the national economy; Breakers Ahead: Cause of the Present Crisis (1896); and The Theory and Practice of Taxation (1900).

It is an account of the dramatic changes in the world economy transitioning into the Second Industrial Revolution in which Wells documented many of the changes in trade, such as triple expansion steam shipping, railroads, the effect of the international telegraph network and the opening of the Suez Canal.