What is the name of the sky god in the Kalevala?

The sky god in the Kalevala is Ukko.

Ukko is the Finnish god of the sky, thunder, weather, and agricultural fertility. His rain was important to crops, while thunder and lightning were understood as manifestations of his power. In the Kalevala, he is also called Ylijumala, meaning “high god” or “supreme god.”

Ukko’s name means “old man,” and Finnish words connected with thunder preserve his memory: ukkonen means thunder, while ukonilma means “Ukko’s weather.” His traditional weapons include a hammer, axe, or sword, with lightning imagined as the result of striking or throwing such a weapon.

A common mix-up is Ilmarinen, who is also associated with the sky in older Finnic traditions. In the Kalevala, however, Ilmarinen is chiefly presented as the immortal smith who forges the Sampo and the dome of the sky. Väinämöinen is instead the epic’s wise singer and culture hero.