Hanalei Bay, Crescent-shaped bay on the north shore of Kauai, United States.

Hanalei Bay is a wide, crescent-shaped bay on Kauai's north shore, about 2 miles (3.2 km) of beach backed by mountains. A low, tree-covered shoreline across the water holds a cluster of pale multi-story buildings with dark roofs, and a long, low pier extends over the water near the center-right. The town of Hanalei sits at the bay's midpoint.

The bay served as a key anchorage for Hawaiian fishing and trading communities in ancient times. A royal vessel wrecked nearby in 1824, leaving behind remains that were uncovered during archaeological work decades later.

Native Hawaiian families maintain traditional taro farming practices in the fertile wetlands surrounding the bay, continuing centuries-old agricultural methods.

The bay is about 2 miles (3.2 km) of beach, with the town of Hanalei at its midpoint and the Hanalei River entering at the northeast end near Princeville. In summer the water suits mooring, stand-up paddle boarding and swimming; in winter the surf grows large and draws surfers. The covered Hanalei Pier near Black Pot beach is a long-standing spot for fishing and picnicking.

The royal yacht Pride of Hawaii sank here on 5 April 1824 after striking a reef about a hundred yards offshore; the crew was believed drunk. A 40-foot stern section was found during the 1995–2000 Smithsonian excavation, documented, then reburied where it lay.