The Æsir are one of the two main families of gods in Norse mythology, the other being the Vanir. They are primarily associated with power, order, and the ruling of the cosmos, with notable members including Odin, Thor, and Frigg. The Æsir are often depicted as warriors and leaders, playing a central role in various myths, including the creation of the world and the events leading up to Ragnarök, the end of the world in Norse belief.

The term Æsir comes from Old Norse, and its plural form is used to denote multiple gods, while the singular form is "Aesir." The Æsir are often contrasted with the Vanir, who are associated with fertility and prosperity. Important myths involving the Æsir include the creation myth in which they shape the world from the body of the primordial giant Ymir and the tales of their struggles against the giants. Understanding the Æsir is crucial for studying Norse mythology and its influence on literature and culture.