Pierre de Sonnaz (died 1410) was a Roman Catholic prelate who served as Bishop of Aosta (1399âÂÂ1410).
On 31 October 1399, Pierre de Sonnaz was appointed during the papacy of Pope Boniface IX as Bishop of Aosta. On 25 January 1400, he was consecrated bishop by Jacques de' Cavalli, Bishop of Vercelli, with Boniface della Torre, Bishop of Ivrea, serving as co-consecrators. He served as Bishop of Aosta until his death in 1410.