Wheat gluten, also called seitan ([ˈseɪtɑn]), wheat meat, gluten meat, or simply gluten, is a food made from the gluten of wheat. It is made by washing wheat flour dough with water until all the starch dissolves, leaving insoluble gluten as a gummy mass, which is subject to further processing. Wheat gluten, although not as well known, is an alternative to soybean-based meat substitutes, such as tofu; some types of wheat gluten have a texture more like that of meat than tofu has, because of their chewy and/or stringy texture. Wheat gluten often is used instead of meat in Asian, vegetarian, Buddhist, and macrobiotic cuisines. Simulated duck is a common use for wheat gluten.

Wheat gluten is most popular in China, where it was first developed, as well as in the cuisines of other East and Southeast Asian nations. In Asia, it is commonly found on the menus of restaurants catering primarily to Buddhist customers who do not eat meat.

Because it was first popularized in western nations during the second half of the 20th century through its promotion by proponents of the macrobiotic diet, seitan (the name by which it is known in macrobiotic circles) is also the name by which wheat gluten is best known in most English-speaking nations. In the West, prepared wheat gluten is generally available only in Asian markets and health food stores (although gluten flour is commonly available in supermarkets).