The Diocese of Ragusa () is a Latin diocese of the Catholic Church in south-eastern Sicily. It was erected in 1950. It is a suffragan of the Archdiocese of Siracusa.
When created on 6 May 1950, by Pope Pius XII, from territory drawn from the Archdiocese of Siracusa, the parish church of San Giovanni Battista in Ragusa was erected into a cathedral, and provided with a Chapter of canons.
On 11 July 1950, a decree of the Sacred Consistorial Congregation removed the territory of the commune of Giarratana, 26 km north of Ragusa, along with its parishes, from the diocese of Noto and attached them to the diocese of Ragusa.
The diocese of Ragusa remained tied to that archdiocese of Siracusa aeque personaliter, in the person of Archbishop Ettore Baranzini, who held the title Bishop of Ragusa as well. The Diocese of Ragusa became fully independent on 1 October 1955, with the appointment of a bishop of its own, Francesco Pennisi.