Born in Hastings-on-Hudson, New York, in 1925, William P. Daley developed an interest in art at an early age, and was encouraged by his parents William and Alice. In 1943 Daley finished high school and enlisted in the Army Air Corps. When the war ended, he returned home, and with the help of the G.I. Bill, completed a B.S. in Art Education from Massachusetts College of Art, and a M.A. from the Teachers College at Columbia University. While at the Massachusetts College of Art he met and married fellow student Catherine Stennes. They had three children together, Barbara, Charlotte, and Thomas.
Originally intending to focus on painting, Daley discovered his love for ceramics while in art school. Much of his early work after graduation consisted of architectural and sculptural commissions. From 1961 to 1965 he held teaching positions as a ceramics instructor at the University of Northern Iowa, State University of New York at New Paltz, Philadelphia College of Art and Design, and the State University of New York at Fredonia. In 1965 he settled in Elkins Park, Pennsylvania and returned to the Philadelphia College of Art and Design, University of the Arts. There he taught in both the Industrial Design and Craft Department until his retirement from the college in 1990. When not teaching in the classroom, and even after retirement, Daley traveled extensively giving workshops and lectures at art centers, high schools, colleges, and universities. He has won several awards for teaching in the arts, including the College Art Association of America Distinguished Teaching of Art Award in 1991.
Daley became an active member of the crafts movement in Philadelphia, co-founding the Philadelphia Council of Professional Craftsmen. The Helen Drutt Gallery opened in Philadelphia in 1974 and gave Daley his first one man show there. Later, the gallery would become Daley's primary dealer. A self-proclaimed "mud man" and maker of "cosmic pots," Daley has focused throughout his career on the issues of the ceramic vessel, using drawings to explore his ideas. In 1994 the Renwick Gallery held a retrospective entitled, "William Daley: Ceramic Works and Drawings" which featured thirty years of his work. William Daley is still producing new work today.