Horse Island is the name of several places, including:

• Horse Islands (Newfoundland and Labrador)
• Horse Island (Lake Winnipeg), Manitoba

• Horse Island, County Clare
• Horse Island, County Cork
• Horse Island, County Kerry

• Horse Island, County Down, a townland of County Down
• Horse Island, County Fermanagh, a townland of County Fermanagh

• Eilean nan Each (Horse Island), one of the Small Isles off the coast of Skye
• Horse Isle in the Firth of Clyde, North Ayrshire
• Horse Island, Summer Isles in the Summer Isles
• Horse Holm in the Shetland Islands, sometimes shown as Horse Island

• Horse Island (Connecticut)
• Horse Island (Maryland)
• Horse Island (Michigan)
• Horse Island (New Mexico)
• Horse Island (New York), site of the Horse Island Light in Sackets Harbor, New York
• Horse Island (Rockville, South Carolina), listed in the National Register of Historic Places
• Horse Island (Texas)

• Wild Horse Island, Montana
• Hrossey (meaning "horse island"), the old name of Mainland, Orkney, Scotland
• Eilean nan Each (Horse Island), Small Isles, Scotland
• Hestur ("Horse" in Faroese), an island in the Faroe Islands
• Horsey Island (disambiguation)