卡尔马联合（丹麦语、瑞典语、挪威语：Kalmarunionen），是1397年至1524年由斯堪的纳维亚的丹麦、瑞典（包括芬兰）和挪威（包括冰岛、法罗群岛、格陵兰、昔德兰和奥克尼）为主组成的共主邦联。1397年6月在瑞典卡尔马城结成的联盟后，挪威、瑞典和丹麦三个王国共同拥戴一个君主。各国交出其主权，但无损各自的独立地位及分歧的利益。不过从1430年代开始，瑞典贵族对于丹麦及荷尔斯泰因在管治中所占的主导地位大为不满，成为了联盟继续的阻碍，并引起纠纷。到了1523年瑞典贵族古斯塔夫·瓦萨成为了瑞典国王后，联盟瓦解。卡尔马联盟在翌年正式结束，从玛格丽特一世开始，历任5位君主及12位摄政官，合共93年。不过其余属地则以丹麦-挪威的名义继续由奥尔登堡王朝管治多个世纪，直到拿破仑战争后两国结束联盟关系。

The Kalmar Union or Union of Kalmaris (Danish, Norwegian and Swedish:Kalmarunionen; Latin:Unio Calmariensis) was a state that brought together the Scandinavian nations from 1397 to 1523.

It was a personal union that joined under a single monarch the three kingdoms of Denmark, Sweden (then including Finland), and Norway, together with Norway's overseas dependencies (then including Iceland, Greenland, the Faroe Islands and the Northern Isles). The Union was not quite continuous; there were several short interruptions. Legally the countries remained separate sovereign states, but with their domestic and foreign policies being directed by a common monarch.