Joseph was born in Paris, one of the 11 sons of Claude Delisle (1644–1720). Like many of his brothers, among them Guillaume Delisle, he initially followed classical studies. Soon however, he moved to astronomy under the supervision of Joseph Lieutaud and Jacques Cassini. In 1714 he entered the French Academy of Sciences as pupil of Giacomo Filippo Maraldi. In the next year he discovered Arago spot a century before Arago. Though he was a good scientist and member of a wealthy family he did not have much money.