ISI mark is a certification mark for industrial products in India. The mark certifies that a product conforms to the Indian Standard, mentioned as IS:xxxx on top of the mark, developed by the Bureau of Indian Standards (BIS), the national standards body of India.

The ISI mark is by far the most recognized certification mark in the Indian subcontinent. The name ISI is an abbreviation of Indian Standards Institute, the former name of the Bureau of Indian Standards. The ISI mark is mandatory for certifying products to be sold in India, like many of the electrical appliances, viz; switches, electric motors, wiring cables, heaters, kitchen appliances, etc., and other products like portland cement, LPG valves, LPG cylinders, automotive tyres, etc. But in the case of most other products it is voluntary.