Canajoharie is a town in Montgomery County, New York, United States. The population was 3,730 in 2010. Canajoharie is located south of the Mohawk River on the southern border of the county. The Erie Canal passes along the northern town line. There is also a village of Canajoharie in the town. Both are east of Utica and west of Amsterdam. These were settled as European-American jurisdictions, named for the historic Mohawk village of the same name, which was also known as the Mohawk Upper Castle.