Jain vegetarianism is the diet of the Jains, the followers of Jainism. It is the most strict form of religiously-motivated diet regulation in the Indian subcontinent. The diet not only excludes meat, fish and eggs, but also does not include potatoes, onions, garlic, carrots and other roots and tubers.

Jain objections to the eating of meat and fish are based on the principle of nonviolence (ahimsa, literally "non-injuring"). Every act by which a person directly or indirectly supports killing or injury is seen as violence (himsa), which creates harmful karma. The aim of ahimsa is to prevent the accumulation of such karma. The extent to which this intention is put into effect varies greatly among Hindus, Buddhists and Jains. Jains consider nonviolence to be the most essential religious duty for everyone (ahinsā paramo dharmaḥ, a statement often inscribed on Jain temples). It is an indispensable condition for liberation from the cycle of reincarnation, which is the ultimate goal of all Jain activities. Jains share this goal with Hindus and Buddhists, but their approach is particularly rigorous and comprehensive. Their scrupulous and thorough way of applying nonviolence to everyday activities, and especially to food, shapes their entire lives and is the most significant hallmark of Jain identity. A side effect of this strict discipline is the exercise of asceticism, which is strongly encouraged in Jainism for lay people as well as for monks and nuns.