腓特烈一世（红胡子）（德语：Friedrich I Barbarossa，约1122年－1190年6月10日）霍亨斯陶芬王朝（House of Hohenstaufen）的罗马人民的国王（1152年－1190年在位）和神圣帝国皇帝（1155年加冕）。他也是德意志的士瓦本公爵（称腓特烈三世，1147年起）和意大利国王（1154年－1186年）。他的父亲是士瓦本公爵腓特烈二世，母亲是巴伐利亚的朱迪丝（属韦尔夫家族）。按亲属关系，他是国王康拉德三世的侄子。

Frederick I (German:Friedrich; 1122 – 10 June 1190), also known as Frederick Barbarossa, was the Holy Roman Emperor from 1155 until his death. He was elected King of Germany at Frankfurt on 4 March 1152 and crowned in Aachen on 9 March 1152. He became King of Italy in 1155 and was crowned Roman Emperor by Pope Adrian IV on 18 June 1155. Two years later, the term sacrum ("holy") first appeared in a document in connection with his Empire. He was later formally crowned King of Burgundy, at Arles on 30 June 1178. He got the name Barbarossa from the northern Italian cities he attempted to rule: Barbarossa means "red beard" in Italian; in German, he was known as Kaiser Rotbart, which has the same meaning.