Paul Hadley was born in Indianapolis and attended Shortridge High School before transferring to Manual Training High School to study under Otto Stark. Upon graduation, he continued his art studies at the Pennsylvania Museum and School of Industrial Art in Philadelphia, where he became skilled in interior design and watercolor work.
In 1916, Hadley designed his best-known creation—Indiana’s State Flag. In celebration of the state’s centennial, the Indiana Daughters of the American Revolution (DAR) sponsored a flag competition. Hadley’s design won the top prize and was officially accepted by the Indiana General Assembly in 1917.
Hadley painted watercolors of local landscapes in his studio in the Union Trust building. In addition, he joined the faculty of the John Herron Art Institute in 1922. He taught classes in watercolor and interior design there for 10 years. He later served as assistant curator at the John Herron Art Museum.
Hadley’s watercolors brought him many awards in the annual Hoosier Salon, Indiana Artists Club, and Indiana State Fair art exhibitions.