Waddell is an unincorporated community in Maricopa County, Arizona, United States, northwest of the city of Phoenix. Waddell is named after Donald Ware Waddell, a native of Ohio, who was a partner in the New York City investment firm of Brandon, Gordon and Waddell. It was this firm that organized the private financing for construction of the dam for the water reclamation project that creates Lake Pleasant. The intended Waddell town site was laid out by Donald W.