Holyoke is a city in Hampden County, Massachusetts, United States, on the banks of the Connecticut River. It is part of the Springfield, Massachusetts Metropolitan Statistical Area. The city was named after Elizur Holyoke, who explored the area in 1660. One of the first planned industrial communities, Holyoke's nickname is "The Paper City." Holyoke is located at 42° 12' 11"N, 072° 37' 26"W.

The region of the Connecticut River Valley was first inhabited by Englishmen in 1633 by virtue of a post established at Windsor by traders from the Plymouth Plantation. Very shortly it became subject to rival claims on the part of New Netherlands, the Massachusetts Bay Colony and Plymouth. The Massachusetts Bay men explored the overland route to the "Great River." In 1635-36, a warehouse and wharf, for purposes of trading with the Indians, was constructed in nearby Agawam. Out of this "trading post" grew Springfield, which later evolved into West Springfield, whose third Parish, called North Parish, or "Ireland Parish," became Holyoke. Holyoke was first settled in 1745 and was officially incorporated in 1850.

The first post office in the area was called Ireland and was established June 3, 1822, with Martin Chapin as first postmaster. It was discontinued in 1883. Another post office called Ireland Depot was established February 26, 1847, with John M. Chapin as first postmaster and had its name changed to Holyoke (with George Whittle as first postmaster) March 14, 1850.

A part of Northampton known as Smiths Ferry was separated from the rest of the town by the creation of Easthampton in 1809, and the shortest path to downtown Northampton was on a road near the Connecticut River oxbow, which was subject to frequent flooding. The neighborhood became the northern part of Holyoke in 1909.

Holyoke had few inhabitants until the construction of a dam and the Holyoke Canal System in 1849, and the subsequent construction of water-powered mills, particularly paper mills. At one point over 25 paper mills were in operation in the city, and the population exploded from 4,600 in 1885 to over 60,000 in 1920. In 1888, Holyoke's paper industry spurred the foundation of the American Pad & Paper Company, which as of 2007 is one of the largest suppliers of office products in the world. As an early planned industrial town, its rectilinear street grid is noteworthy in a region where few streets are parallel or even straight.

However, Holyoke's fortunes took a turn for the worse as manufacturing became an ever-shrinking part of the American economy. In the past several years, there have been efforts to bring jobs into Holyoke and diversify the economic base. The retail sector has been a major employer in the city since the Holyoke Mall opened in 1979, as well as the nearby Holyoke Crossing shopping center. This has also provided the city with a large and steady tax base, contributing over $7 million dollars in taxes annually. Despite these improvements, Holyoke is one of the poorest cities in Massachusetts, with about 50% of schoolchildren living below the poverty line. It is sister-cities with Deltona, Florida.

Holyoke, Massachusetts is home to the Holyoke Mall at Ingleside, one of the biggest shopping malls in New England. Holyoke also contains the Log Cabin Banquet and Meeting House, which has won numerous awards and recognitions and is claimed to be one of the top banquet facilities in New England.

Holyoke Public Library, found at 335 Maple Street, is one of the very few examples of neoclassical architecture in the city of Holyoke. It sits firmly on Library Park, which was donated by the Holyoke Water Power Company in 1887. In 1870 the library was originally located in a room in the old Appleton Street School. In 1876 it moved to a large central room on the main floor of City Hall. It remained there until it was determined that it had outgrown the space and a modern facility was required. Holyoke's citizens were charged to raise money to construct the library building and provide additional books. Under the leadership of Henry Chase, $95,000 was raised. William Whiting and William Skinner, each gave $10,000. Joseph Clough, the architect in charge of designing the building, gave his services gratis because his daughter was a faithful patron of the library. It opened officially in 1902. At the dedication ceremony William Whiting, who was library president at the time, referred to the library as the "people's college," and added that: "A library is as much a part of the intellectual life of a community as its schools, and should be supported generously as part of our educational system. Within these walls you will find authors devoted to literature, arts and science, and they are free to any who will ask. We can say to the citizens of Holyoke you have only to ask her and you will find knowledge to make your life useful and happy."

On February 9, 1895, William G. Morgan invented volleyball at a YMCA in Holyoke. The YMCA where volleyball was actually invented was demolished, and has been replaced by a dollar store on the corner of Appleton and High Streets. The Volleyball Hall of Fame resides in Holyoke at Heritage State Park and inducts a new class of athletes, coaches and contributors every October.

Holyoke has the highest percentage of Puerto Ricans of any city in the United States outside Puerto Rico. Always a city of working-class immigrants, the first wave of mill workers was predominantly Irish, and Holyoke is still home to the second-largest St. Patrick's Day parade in the United States, surpassed only by the New York City parade. Held annually since 1952 on the Sunday following St. Patrick's Day, the parade draws thousands of people from across the region and nation. In the 1850s, mills began to recruit French-Canadians, who were viewed as more docile and less likely to form labor unions. Later waves of immigration and migration led to significant communities of Germans, Poles, Jews, and then, starting in the 1950s, Puerto Ricans, and other Latino groups. Today Latinos form the largest minority group in the city. Unlike most immigrants to Holyoke, Puerto Ricans were already American citizens when they migrated here, due to the Jones-Shafroth Act of 1917. The Latino community of Holyoke holds an annual Puerto Rican Day parade on the third weekend in July as part of an Annual Hispanic Family Festival held by La Familia Hispana, inc. Every year the parade grows in popularity.