Michael Daniel Harter (April 6, 1846 – February 22, 1896) was an American banker and politician. He served two terms as a U.S. Representative from Ohio during the 1890s.

Born in 1846 in Canton, Ohio, Harter attended public schools. He was a grandson of Robert Moore, who served as a U.S. Representative from Pennsylvania during 1817–1821.

Harter engaged in mercantile pursuits and banking. He established the Harter Bank in 1866.^[1] In 1869, he moved to Mansfield, Ohio, and at the age of 23 became treasurer and manager of the Aultman & Taylor Company upon its organization. He also established the Isaac Harter Milling Company in Fostoria, Ohio, the largest producer of flour in the state.^[1]

A Democrat, Harter was elected to the Fifty-second and Fifty-third Congresses, spanning March 1891 to March 1895. In Congress, he was strongly in favor of the gold standard, and against free silver, views in opposition to his own party. His views won out during the Panic of 1893, when Congress, in special session, repealed the Sherman Silver Purchase Act.^[1] Harter declined to be a candidate for renomination to a third term.

Harter was married to Mary L. Brown in 1869, and they had three sons and two daughters. After serving in Congress, he moved to Philadelphia but spent his summers in Mansfield. Harter died by suicide in Fostoria in February 1896.^[2] His wife and children, except one daughter, survived him.^[1] He was interred in Mansfield Cemetery.