Oliver Phelps (1749 - 1809) was born in Windsor, Connecticut and moved to Massachusetts in his younger years to become a merchant. During the Revolution he became Deputy Commissary of the Colonial Army.

In 1789 he entered into partnership with Nathaniel Gorham, and they purchased most of western New York from the state of Massachusetts. See: Phelps and Gorham Purchase.

At first they thought to make (modern day) Geneva their headquarters, but discovered by survey, just in time, that their site was just east of their boundary. So they chose Canandaigua, at the head of Canandaigua Lake, as the seat of the new Ontario County. The name Canandaigua is derived from the Iroquois word "Kanandarque" which means "chosen spot." It was the site of the principal village of the Seneca Indians, burned during the war in the Sullivan Expedition.

After the purchase, Phelps opened a land sales office in Suffield, Connecticut and another in Canandaigua. He was appointed the first judge of Ontario County (1789 - 1793), even before he moved there. He built the first framed house in Canandaigua in 1792 then built a mill. He served in Congress from 1803 to 1805.

Despite vast land holdings that were worth a fortune, economic fluctuations and slow land sales caused Phelps to get into financial difficulty. The reverses forced him to sell his Suffield home and his interest in the Harfort National Bank and Trust Co.

Purchasers of the land also had difficulty paying off the mortgages which he held. He was generous in extending terms to them, to his own loss. Phelps died in 1809 in debtors prison in the town he sold and helped develop.