阿历克塞三世·安格洛斯（希腊语：Αλέξιος Γ’ Άγγελος，约1153年－1211年）拜占庭帝国皇帝（1195～1203年在位），是安德罗尼柯·安格洛斯的次子，伊萨克二世的弟弟。1195年在军队的支持下发对政变，将其兄伊萨克二世废黜，刺瞎后囚禁起来。统治期间，拜占庭在巴尔干被保加尔人击败。

1023年，在十字军的帮助下，伊萨克二世和其子阿历克塞四世攻入君士坦丁堡，阿历克塞三世携带着其搜刮的财宝逃到色雷斯，先后在希腊和小亚细亚各地流亡，最后死于尼西亚（今土耳其伊兹尼克）的一家修道院。

Alexios III Angelos (Greek:Αλέξιος Γ' Άγγελος) (c. 1153–1211) was Byzantine Emperor from March 1195 to July 17/18, 1203. A member of the extended imperial family, Alexios came to throne after deposing, blinding, and imprisoning his younger brother Isaac II Angelos. The most significant event of his reign was the attack of the Fourth Crusade on Constantinople in 1203, on behalf of Alexios IV Angelos. Alexios III took over the defense of the city, which he mismanaged, then fled the city at night with one of his three daughters. From Adrianople, and then Mosynopolis, he unsuccessfully attempted to rally his supporters, only to end up a captive of Marquis Boniface of Montferrat. He was ransomed, sent to Asia Minor where he plotted against his son-in-law Theodore Laskaris, but was eventually arrested and spent his last days confined to the Monastery of Hyakinthos in Nicaea, where he died.