Robert Boal (November 15, 1806 – June 12, 1903) was an American politician and physician from Pennsylvania. After schooling in Ohio, Boal moved to Lacon, Illinois, where he practiced medicine for thirty years. Boal was elected to the Illinois Senate in 1844, serving for four years. He returned to the General Assembly with an 1856 election to the Illinois House of Representatives. After serving a pair of two-year terms, he was made a trustee of the Illinois Institute of the Deaf and Dumb. During the Civil War, Boal examined soldiers from his congressional district. He later directed the Peoria State Hospital.