North Amherst is located in the northern part of the town of Amherst at (42.406192, -72.521217). It is bordered to the south by the Amherst Center CDP and to the southwest by the town of Hadley. The CDP border follows the Mill River north from the Hadley town line, then east across Massachusetts Route 116 as far as Massachusetts Route 63. The border then follows Pulpit Hill Road, Mill Street, Sand Hill Road, and Pine Street east to the New England Central Railroad line, which it follows south to Tilson Farm Road. The CDP boundary then proceeds west along Tilson Farm Road and Eastman Lane to North Pleasant Street, which it follows north to a brook near the Hadley town line.