Ajinomoto Co. Inc. (味の素株式会社, Ajinomoto Kabushiki-gaisha) (TYO: 2802), is a Japanese food and chemical corporation which produces seasonings, cooking oils, TV dinners, sweeteners, amino acids and pharmaceuticals. In particular it is the world's largest producer of aspartame, with a 40% global market share.

The literal translation of Aji no Moto is “Essence of Taste,” used as a trademark for the company’s original monosodium glutamate (MSG) product. Thanks to the company's eminent status, its brand has found its way even to notable Asian language dictionaries as a half-synonym for MSG.

As of Feb 2009, Ajinomoto produces around 33% of the world’s MSG.^{[citation needed]} Its head office is located in Chūō, Tokyo.

Ajinomoto is active in 100 countries and regions worldwide, employing around 24,861 people as of 2004. Its yearly revenue stands at around US$9 billion.

Ajinomoto’s signature product, monosodium glutamate (MSG; グルタミン酸ナトリウム) seasoning, was first marketed in Japan in 1909, having been discovered and patented by Kikunae Ikeda. He found that the most important compound within seaweed broth for common use was actually a glutamate salt, which seemed to give out a unique taste sensation, which he dubbed umami. As the simplest and safest such salt for human consumption, the popularity of MSG helped the company rapidly expand to other countries, with Ajinomoto U.S.A., Inc. established in 1956.^{[citation needed]}