Diego Venini (4 October 1889 – 20 July 1981) was an Italian Catholic archbishop who served as the private secretary of Pope Pius XI and later the Secret Almoner of the Office of Papal Charities.

He was born on 4 October 1889 in Fiumelatte, a hamlet of Varenna, a small town on the eastern shore of Lake Como, at the time in the Archdiocese of Milan.

After completing his studies at the archdiocesan seminary, he was ordained a priest by Cardinal Archbishop Andrea Carlo Ferrari on 6 July 1913, the day his mother died.

On 13 June 1913, Pope Benedict XV appointed Achille Ratti as the cardinal Archbishop of Milan.

[2] In his role as papal almoner, he participated in the funerals of Pius XII and John XXIII and in the Conclaves of 1958 and 1963.