The Diocese of Duvno (Latin: Dioecesis Dumnensis; Dioecesis Dalminiensis; Croatian: Duvanjska biskupija) was a Latin rite diocese of the Catholic Church that was established in the 14th century with a seat in present-day Tomislavgrad in Bosnia and Herzegovina. From the late 17th century onwards, it was administered by the bishops of Makarska, though by the 19th century it was only a titular see. On 5 July 1881 Pope Leo XIII incorporated it into the newly established Diocese of Mostar-Duvno. Its last titular bishop was Cyryl Lubowidzki, who held the title until 1897, when it was formally suppressed.