Matthew Stanley Quay (September 30, 1833 - May 28, 1904) was an immensely powerful Pennsylvania political boss; "kingmaker" (Benjamin Harrison, 1888).

Quay was born in Dillsburg, York County, Pennsylvania. He graduated at Jefferson College (now Washington and Jefferson College) in 1850 and was admitted to the bar in 1854. He served in various capacities in the Civil War, and in 1865-1867 was a member of the state House of Representatives, becoming secretary of the commonwealth in 1873-1878 and again in 1879-1882, recorder of Philadelphia in 1878-1879, and state treasurer in 1886-1887. He was chairman of the Republican national executive campaign committee in 1888, and was a member of the United States Senate in 1887-1899 and again in 1901-1904. For nearly twenty years he dominated the government of Pennsylvania, and also played a very prominent part in national affairs. In 1899 he was brought to trial on a charge of misappropriating state funds, and, although he was acquitted, the feeling among the reform element in his own party was so bitter against him that the legislature was deadlocked and his re-election was postponed for two years.

• 1833: Born Dillsburg, York County, Pennsylvania; educ. Beaver Academy.
• 1850: Jefferson College; law student with firm in Pitts .
• 1851-53: Mississippi.
• 1854: Admitted to Beaver County bar.
• 1855: Beaver County, prothonotary; marries Agnes Barclay.
• 1856: Beaver County, prothonotary.
• 1859: Beaver County, prothonotary.
• 1861: 10th Pa. Reserves (Lt., Lt.-Col.).
• 1862: Governor Andrew Curtin, private sec'y.
• 1862: 134 Pa. Volunteers, commissioned, Col. (Aug.)
• 1862: Leaves 134 Pa. Volunteers (health) (7 Dec.)
• 1862: Battle of Marye's Heights (13 Dec.)
• 1864: Pa. state legislature.
• 1865: Pa. state legislature.
• 1866: Pa. state legislature.
• 1869: Founds *Beaver Radical*
• 1873-78: Pa. state secretary.
• 1878-79: City of Philadelphia, Recorder. (resigned)
• 1879-82: Pa. state secretary. (named Jan.; resiged Oct.)
• 1886-87: Pa. state treasurer.
• 1887: U.S. Senate.
• 1888: Republican National Committee, Chairman.
• 1892: U.S. Senate.
• 1897: Not reeected; term expires 1898.
• 1901: U.S. Senate
• 1904; Death.

He lost reelection, 1898 (charges of corruption, acquitted 1899).

He prevented all other candidates from securing election to Senate in 1888; was appointed to vacant seat by Governor Beaver (whom he controlled) in 1901. Served in U.S. Senate from 1901 until death in 1904; buried in Beaver County, Pennsylvania.