Tryon County, New York was a county in New York, part of the Province of New York, named after Governor William Tryon. In 1784 the county was renamed Montgomery County, New York after General Richard Montgomery.

Tryon County was created in 1772 from part of Albany County, partly at the instigation of William Johnson. Because the county had no clear western boundary, it extended, in theory, to the far side of North America. Nevertheless, the reality of the Iroquois Confederation in a large area encompassing Oneida Lake meant that the territory was not available to settlers, especially with Johnson protecting the interests of the native inhabitants. In fact, part of Johnson's motivation in creating the county had been to serve the interests of native Americans.

Prior to the outbreak of the American Revolution some members of the county formed Committees of Safety to harass their loyalist neighbors, eventually causing many to flee to the safety of Canada. When the war abated in the area, the name of the hated governor was removed. The county began to fill again, more than compensating for the loss of life during the war.

As Montgomery County, this large tract was partitioned into most of the counties in upstate New York. The first created county was Ontario County in 1789, and the last was Fulton County in 1838.

See also

• List of New York counties
• List of extinct U.S. counties
• Montgomery County, New York
• Albany County, New York