Agostino Ciasca (secular name Pasquale) (born at Polignano a Mare, in the province of Bari, 7 May 1835; died at Rome, 6 February 1902) was an Italian Augustinian and Cardinal.

In 1866 he obtained the chair of Hebrew in the College of Propaganda, and later took part in the First Vatican Council in the quality of theologian and as interpreter for the Oriental bishops.

In 1891 he was created Titular Archbishop of Larissa with the appointment to the office of prefect of the Vatican Archives; in the same year he was sent by the Holy See to preside over the Ruthenian synod at Lemberg.

[2] He published (1885–89) the extant fragments of a very ancient Coptic version of the Old Testament, from manuscripts in the Borgia (Propaganda) Museum.

He discovered and edited (1888) of an Arabic version of the Diatessaron of Tatian, a text of importance for the history of the Canon of the New Testament (cf.