Geneseo /ˌdʒɛnɪˈsiːoʊ/ is a town in Livingston County in the Finger Lakes region of New York, United States.

Near Geneseo was the largest[clarification needed] Seneca village, Jo’néhsiyoh, a center of power for the Haudenosaunee Confederacy.

The alliance's raids from the west were a major threat to the American cause, and General Washington sent the Sullivan Expedition to neutralize the Haudenosaunee.

As Sullivan's army approached Geneseo with their "scorched earth" policy, the Senecas repeatedly fell back.

When Sullivan's troops arrived and found the savagely mutilated bodies, they became enraged and destroyed anything that could support the Haudenosaunee.

The brothers came to the Genesee Valley from Connecticut as agents of their uncle, Colonel Jeremiah Wadsworth, to care for and sell the land he purchased.

The Wadsworths were part of the negotiations of the Treaty of Big Tree between Robert Morris and the Senecas at the site of Geneseo in 1797.

Geneseo was the birthplace of Eliza Emily Chappell Porter in 1807, a nurse, teacher, school builder, and Underground Railroad operative during the Civil War.

In 1991, the United States Department of the Interior designated large parts of the village a National Historic Landmark.

The valley of the Genesee River is wide and fertile, with some of the best agricultural land in New York, but it was very prone to flooding, and Geneseo suffered several bad floods until the United States Army Corps of Engineers' construction of the Mount Morris Dam upstream of the community in the 1950s.

The increasing presence of big-box stores on Route 20A has been welcomed by some residents, who appreciate the convenience of nearby retailers, and discouraged by others, who oppose the suburbanization of the small town.

The Association for the Preservation of Geneseo (APOG) is a civic organization dedicated to preserving, improving, and restoring the places of civic, architectural, and historic interest to Geneseo and to educate members of the community to their architectural and historical heritage.

[8] Sweet Briar and the Wadsworth Fort Site are listed on the National Register of Historic Places.

(Clockwise) Geneseo has a mild climate; summers typically bring temperatures between 60–80 °F (16–27 °C), while winters average 15–35 °F (−9–2 °C).