Holyoke is a city in Hampden County, Massachusetts, United States, that lies between the western bank of the Connecticut River and the Mount Tom Range. As of the 2010 census, the city had a population of 39,880. As of 2019, the estimated population was 40,117. Located 8 miles north of Springfield, Holyoke is part of the Springfield Metropolitan Area, one of the two distinct metropolitan areas in Massachusetts.
Holyoke is among the early planned industrial cities in the United States. Built in tandem with the Holyoke Dam to utilize the water power of Hadley Falls, it is one of a handful of cities in New England built on the grid plan. During the late 19th century the city produced an estimated 80% of the writing paper used in the United States and was home to the largest paper mill architectural firm in the country, as well as the largest paper, silk, and alpaca wool mills in the world. Although a considerably smaller number of businesses in Holyoke work in the paper industry today, it is still commonly referred to as "The Paper City".