 On 13 July 2007, Pope Benedict XVI named Delpini as the Titular Bishop of Stephaniacum, and Tettamanzi consecrated Delpini as a bishop on the following 23 September.Cardinal Angelo Scola made him as the vicar general of the archdiocese in 2012.On 7 July 2017, Pope Francis appointed him as the new Archbishop of Milan, where he was installed on 9 September.