天主教教宗本笃三世（858年4月7日卒于罗马市），（在位期间：855年9月29日－858年4月7日）。

据记载在他当选之前他以其怜悯和好学而着称。

在本笃被选的时候不同获选人的支持者之间爆发了暴乱。一开始他被皇帝所支持的对立教宗达西三世推翻和关押，后来达西受到的支持减弱后他被营救并与855年9月29日正式被立为教宗。

本笃三世得以加固教宗在教会内的地位。他主张婚姻是神圣的，与贵族和高级僧侣的习俗败坏斗争。此外他对英国非教会人员罢免主教提出了抗议。在他的执政期间天主教与拜占庭东正教之间的矛盾加深。

有人提出认为在本笃三世与良四世之间有过一个女教宗琼安，但这个说法被天主教廷反驳。提这个说法的人认为琼安的名字是在17世纪才被从教宗消除的。有人甚至认为，由于对本笃三世本人的记载非常少，实际上历史上并没有这个人，他是被发明来取代女教宗琼安的。

Pope Benedict III (Latin:Benedictus III; died 17 April 858) was Pope from 29 September 855 to his death in 858.

Little is known of Benedict's life before his papacy. His father was Peter. He was educated and lived in Rome and was cardinal priest of the church of San Callisto at the time of his election. Benedict had a reputation for learning and piety. He was elected upon the refusal of Hadrian, the initial choice of the clergy and people. A group of important people preferred a different candidate, Anastasius. This latter group had Benedict's election disavowed and Anastasius installed. However, popular opinion was so strong that Benedict's consecration was allowed. The envoys of Holy Roman Emperor Louis II forced Benedict to handle Anastasius and his adherents leniently. The schism helped to weaken the hold of the emperors upon the popes, especially upon their elections.