The religion most closely associated with Diwali is Hinduism.
Diwali, also called Deepavali, is primarily a Hindu festival of lights. Its central symbolism is the victory of light over darkness, good over evil, knowledge over ignorance, and dharma over adharma. Many Hindu communities associate the festival especially with Lakshmi, the goddess of prosperity, and Ganesha, the deity linked with wisdom and removing obstacles.
The festival’s stories vary by region. In northern India, Diwali is strongly connected with Rama’s return to Ayodhya after defeating Ravana and completing 14 years of exile. Other traditions focus on Krishna’s defeat of Narakasura, or on Lakshmi’s worship during the festival’s main night.
Diwali is not exclusive to Hinduism. Jains observe it in connection with Mahavira’s final liberation, Sikhs celebrate Bandi Chhor Divas during the same season, and Newar Buddhists in Nepal also observe related rituals. These associations explain why the other options may appear in discussions of Diwali, but Hinduism remains the festival’s primary religious association.