Chautauqua Lake is a 27-kilometre glacially formed lake running north-south through Chautauqua County, its northern end near the town of Westfield and its southern end at Jamestown. The Institution sits on the western shore of the northern section. The lake is warm enough for swimming through the summer and is popular for fishing — walleye, muskellunge, and largemouth bass are the main catches.
Boat rentals, kayaks, and paddleboards are available within the Institution grounds and at several points around the lake shore. The lake is the backdrop for much of the summer social life at Chautauqua: evening strolls along the shore promenade, boat trips to the other side, and the views from the cottage porches that have made this real estate among the most keenly contested in western New York.