Island Lake is a glacial tarn in the Ruby Mountains, in Elko County in the northeastern part of the state of Nevada. It is located in a hanging valley above Lamoille Canyon near the Road's End Trailhead, at approximately , and at an elevation of 9650 feet (2940 m). It has an area of approximately 7.5 acres (3.0 hectares), and a depth of up to 22 feet (6.7 m). Island Lake is the terminus of a short hiking trail, and is a popular site for day trips, fishing, and camping.
Island Lake is a minor source of flow for Lamoille Creek, which after exiting the mountains passes through the town of Lamoille, meanders down Lamoille Valley, and then merges with the main branch of the Humboldt River.