David Wills was born in Menallen Township, Adams County, Pennsylvania, the son of James Wills, a farmer. He remained on his father's farm until 13 years of age, entering Pennsylvania College (now Gettysburg College) in 1846 from which he graduated with high honors in 1851. He then became a principal of the Academy at Cahaba, Alabama, where he taught one year. In 1853 he entered as a law student in the office of Hon. Thaddeus Stevens at Lancaster, PA, and in 1854 he was admitted to the Bar of Pennsylvania.