Introduction
Vayu is the god of the wind. He is the divine father of Hanuman, and Hanuman is called Pavanaputra, "son of the wind".
This article primarily follows the Valmiki Ramayana. Where a well-known detail comes from a later retelling or tradition, the article identifies it.
Hanuman's father
Hanuman was born to Anjana and Kesari, with Vayu as his divine father. When Indra struck the child Hanuman with his thunderbolt, Vayu withdrew the wind from the world in anger, and the gods had to make peace with him by giving Hanuman boons.
Helping Lakshmana
In the war, Vayu whispered to Lakshmana that only the Brahma weapon could kill Atikaya.