Islip, town, Suffolk County, southeastern New York, on Long Island, on Great South Bay; settled 1683, incorporated 1710. The town, in a seaside resort area, comprises some 20 residential communities, including Islip Village, seat of the town government; Central Islip, home of the New York Institute of Technology-Central Islip (1955); Brentwood, the site of a community college; Oakdale, the site of Dowling College (1959); and Bay Shore and Sayville, each with ferry service to Fire Island. Products include baked goods, electronic equipment, ducks, and clams. The area grew after the arrival of the railroad and the opening of a clam cannery, both in 1867. The town is named for Islip, England.