Preston King (October 14, 1806 – November 12, 1865) was an American attorney and politician who represented New York in the United States Senate from 1857 to 1863.

King entered politics as an ally of Martin Van Buren and was a lifelong opponent of slavery as a member of the Democratic, Free Soil, and Republican parties.

[6] In 1847, when there was an open rupture between the Barnburners and Hunkers at the Democratic State Convention, King was made chairman of the former and Robert H. Morris of the latter.

[7] After the death of President Lincoln, he served as effective White House Chief of Staff during the early days of the Johnson Administration.

"[7] Despairing of success, King killed himself by tying a bag of bullets around his neck and leaping from a ferryboat in New York Harbor on November 13, 1865.