克努特大帝（古挪威语: Knútr inn ríki ，英语：Canute the Great，995年－1035年11月12日），丹麦称克努特二世，英格兰称克努特一世。他继承父亲丹麦国王斯温的王位，对英格兰、丹麦、挪威及部份瑞典进行统治，其辖境享有北海帝国之称。

公元1012年，八字胡斯温率军击败英格兰国王爱塞烈德二世，自称英格兰国王，死后由克努特继承英格兰王位。1016年，他和爱塞烈德二世之子埃德蒙二世订约共治英格兰，结果后者当年11月便告不治，使他完全统治了英格兰。1017年，他跟前英格兰王爱塞烈德的遗孀诺曼第的爱玛结婚。1019年，他的哥哥丹麦国王哈拉尔二世突然死亡，他因此继承了丹麦王位。

Cnut the Great (Old Norse: Knútr inn ríki; c. 995– 12 November 1035), more commonly known as Canute, was a king of Denmark, England and Norway, together often referred to as the Anglo-Scandinavian or North Sea Empire. After his death, the deaths of his heirs within a decade, and the Norman conquest of England in 1066, his legacy was largely lost to history. The medieval historian Norman Cantor has stated that he was "the most effective king in Anglo-Saxon history", although Cnut himself was Danish, not British or Anglo-Saxon.