Girdwood is an unincorporated year-round ski resort community within the Municipality of Anchorage in the U.S. state of Alaska. It lies in a valley in the Chugach Mountains near the end of the Turnagain Arm of Cook Inlet, 36 miles (61 km) southeast of Anchorage proper.

It is surrounded by seven permanent glaciers. Summer activities include hiking, fishing and rafting, but Girdwood is best known for winter skiing and snowboarding at Alyeska Resort on Mount Alyeska. Girdwood also hosts the Girdwood Forest Fair every summer. Girdwood has the northernmost rain forest in the world.

Originally called "Glacier City," Girdwood was founded as a supply camp for placer gold miners with claims along the creeks feeding Turnagain Arm. It was renamed for Colonel James Girdwood, a Belfast-born, Scots-Irish entrepreneur and linen merchant who staked the first four gold claims along Crow Creek in 1896.

The town was moved 2.5 miles (4 km) up the valley after the devastating Good Friday Earthquake of 1964, when the land under the original townsite subsided into Turnagain Arm, putting much of the town below high tide. The land has not all since been reclaimed, as one can still see 'drowned' cabins in the marshy areas where the city formerly extended. Significant earthquakes are a relatively common occurrence for Girdwood and the Kenai peninsula. Evidence has been discovered that indicates the area has seen six major quakes in the past 3300 years.