Henry of Segusio, usually called Hostiensis, was an Italian canonist of the thirteenth century, born at Susa (Segusio), in the ancient Diocese of Turin. He died at Lyon.

The former French diocese of Sisteron existed until the French Revolution. Its see was at Sisteron in southern France and at Forcalquier, in the modern department of Alpes-de-Haute-Provence. Sisteron was the only diocese in France which had two cathedrals. Each cathedral had a Chapter, and the two Chapters voted together when an election was held to elect a new bishop of Sisteron. The diocese of Sisteron was part of the ecclesiastical province of Narbonensis Secunda, whose Metropolitan was the Archbishop of Aix-en-Provence.