Perkūnas was the common Baltic god of thunder, and the second most important deity in the Baltic pantheon after Dievas. In both Lithuanian and Latvian mythology, he is documented as the god of sky, thunder, lightning, storms, rain, fire, war, law, order, fertility, mountains, and oak trees.

Lithuanian mythology is the mythology of Lithuanian polytheism, the religion of pre-Christian Lithuanians. Like other Indo-Europeans, ancient Lithuanians maintained a polytheistic mythology and religious structure. In pre-Christian Lithuania, mythology was a part of polytheistic religion; after Christianisation mythology survived mostly in folklore, customs and festive rituals. Lithuanian mythology is very close to the mythology of other Baltic nations – Prussians, Latvians, and is considered a part of Baltic mythology.