Seal Beach is located in the westernmost corner of Orange County. To the northwest, just across the border with Los Angeles County, lies the city of Long Beach and the adjacent San Pedro Bay. To the southeast are Huntington Harbour, a neighborhood of Huntington Beach, and Sunset Beach, also part of Huntington Beach. To the east lie the city of Westminster and the neighborhood of West Garden Grove, part of the city of Garden Grove. To the north lie the unincorporated community of Rossmoor and the city of Los Alamitos. A majority of the city's acreage is devoted to the Naval Weapons Station Seal Beach military base.