Walter Quintin Gresham (March 17, 1832–May 28, 1895) was an American statesman and jurist. He served as United States Postmaster General, as a judge on the federal circuit court, was a two-time candidate for the Republican presidential nomination and was Secretary of State and Secretary of the Treasury.

He was born near Lanesville, Indiana, and spent two years in an academy at Corydon, Indiana, and one year at the Indiana State University at Bloomington , then studied law, and in 1854 was admitted to the bar. He was active as a campaign speaker for the Republican ticket in 1856, and in 1860 was elected to the Indiana House of Representatives as a Republican from a strong Democratic district. In the House, as chairman of the committee on military affairs, he did much to prepare the Indiana troops for service in the federal army. In 1861, at the outbreak of the American Civil War, he became colonel of the 53rd Indiana Volunteer Infantry , and subsequently took part in Grant's Tennessee campaign of 1862, and Battle of Corinth and Battle of Vicksburg, where he commanded a brigade. In August 1863 he was appointed brigadier-general of volunteers, and was placed in command of the federal forces at Natchez. In 1864 he commanded a division of the 17th Army Corps in Sherman's Atlanta campaign, and before Battle of Atlanta, on July 20, he received a wound which forced him to retire from active service, and left him lame for life. In 1865 he was brevetted major-general of volunteers.

After the war he practised law at New Albany, Indiana, and in 1869 was appointed by President Ulysses S. Grant United States District Judge for Indiana. In April 1883 he succeeded Timothy O. Howe (1816-1883) as Postmaster General in President Chester A. Arthur's cabinet, taking an active part in the suppression of the Louisiana Lottery, and in September 1884 succeeded Charles J. Folger as United States Secretary of the Treasury. In. the following month he resigned to accept an appointment as United States Judge for the Seventh Judicial Circuit.

Gresham was a candidate for the Republican presidential nomination in 1884 and 1888, in the latter year leading for some time in the balloting. Gradually, however, he grew out of sympathy with the Republican leaders and policy, and in 1892 advocated the election of the Democratic candidate, Grover Cleveland, for the presidency. From the March 7, 1893 until his death at Washington, D.C. on May 28, 1895, he was Secretary of State in President Grover Cleveland's Cabinet.

|- style="text-align: center;" | width="30%" |Preceded by:
Charles J. Folger | width="40%" style="text-align: center;" |U.S. Secretary of the Treasury
1884 | width="30%" |Succeeded by:
Hugh McCulloch

|- style="text-align: center;" | width="30%" |Preceded by:
John W. Foster | width="40%" style="text-align: center;" |U.S. Secretary of State
1893–1895 | width="30%" |Succeeded by:
Richard Olney