Agnihotra (अग्निहोत्र) is a Vedic yajña (ritual or sacrifice) performed in orthodox Hindu communities. It is mentioned in the Atharvaveda (11:7:9) and described in detail in the Yajurveda Samhita and the Shatapatha Brahmana (12:4:1). The Vedic form of the ritual is still performed by the Nambudiri Brahmins of Kerala and by a small number of Vaidiki Brahmins in South Asia. Modern versions of the Agnihotra are promoted by various individuals and groups as a non-sectarian ritual for the healing and purification of the atmosphere and as a primary source of vibhuti or sacred ash.

Agnihotra is a tatpuruṣa compound (samāsa), meaning an offering (originally, of milk) into Agni (Latin ignis, etc.) or consecrated fire. It finds earliest mention in the Atharva Veda (1000 BC), vi 97,1, (source Monier Williams) though pouring into the ritual fire was known as early as in the Ṛgveda (c. 1400 BC) and it the closely related Zoroastrian religion (Yasna Haptaŋhāiti).

The central part of the Agnihotra consists of making two offerings of milk into the fire exactly at, slightly before, or even after the time of sunset and sunrise, along with Vedic mantras that relate the fire and the sun to each other: 'agnir jyotir, jyotiḥ sūryaḥ svāhā' in the evening, but the reverse 'sūryo jyotir, jyotir agniḥ svāhā' in the morning. This preserves the sun over night, which is also one of the interpretations of the ritual given in the Samhitas and Brahmanas.