Turmeric (Curcuma longa) (/ˈtɜːrmərɪk/) is a rhizomatous herbaceous perennial plant of the ginger family, Zingiberaceae. It is native to the Indian subcontinent and Southeast Asia, and requires temperatures between 20 and 30 °C (68–86 °F) and a considerable amount of annual rainfall to thrive. Plants are gathered annually for their rhizomes and propagated from some of those rhizomes in the following season.

When not used fresh, the rhizomes are boiled in water for about 30–45 minutes and then dried in hot ovens, after which they are ground into a deep-orange-yellow powder commonly used as a coloring and flavoring agent in many Asian cuisines, especially for curries, as well as for dyeing. Turmeric powder has a warm, bitter, pepper-like flavor and earthy, mustard-like aroma.

Although long used in Ayurvedic medicine, there is no high-quality clinical evidence for use of turmeric or its main constituent, curcumin, as a therapy.