| Honorific-Prefix: | Most Reverend |
| Juan Sierra | |
| Bishop of Segovia | |
| Church: | Catholic Church |
| Diocese: | Diocesep of Segovia |
| Term: | 1370–1374 |
| Predecessor: | Fernando Sarracín |
| Successor: | Hugo de Lamanhania |
| Consecration: | 1367 |
| Consecrated By: | Gómez Manrique (bishop) |
| Death Date: | 16 February 1374 |
| Death Place: | Segovia, Spain |
| Previous Post: | Bishop of Orense (1367–1370) |
Juan Sierra (died 16 February 1374) was a Roman Catholic prelate who served as Bishop of Segovia (1370–1374) and Bishop of Orense (1367–1370).[1]
On 23 August 1361, Juan Sierra was appointed during the papacy of Pope Innocent VI as Bishop of Orense. In 1367, he was consecrated bishop by Gómez Manrique (bishop), Archbishop of Toledo, with Bishop Gundisalvo, Bishop of Viseu, serving as co-consecrator. On 3 October 1370, he was appointed during the papacy of Pope Urban V as Bishop of Segovia. He served as Bishop of Segovia until his death On 16 February 1374.