The Castle Group, Inc., through its subsidiaries, operates in the hotel and resort management industry in the state of Hawaii, New Zealand, and the Commonwealth of Saipan under the Castle Resorts and Hotels trade name. It manages luxury and mid-range resort condominiums and hotels on various islands in the state of Hawaii; and a property located in New Zealand. The company also provides reservations staffing and operation, advertising, sales and marketing, and accounting services to property owners.

The Castle Group, Inc. was incorporated in 1981 and is headquartered in Honolulu, Hawaii.