Semolina is a coarse flour traditionally made from durum wheat. Its high protein and gluten content make it especially suitable for pasta.

Semolina is distinguished from other refined wheat flours by its coarse texture: the Codex Alimentarius specifies that a durum wheat semolina must have grains large enough that no more than 79% pass through a 315-micron textile sieve.

The word "semolina", attested since 1790–1800, is derived from the Italian word semolino, an alteration of semola ('coarse grains', from Latin simila, 'fine flour') with the diminutive suffix -ino. The Latin word is of ultimate Semitic origin, with the original meaning of 'to grind into groats'; cf. Arabic samīd (سميد, 'semolina') and Aramaic səmīḏā (ܣܡܻܝܕܳܐ, 'fine flour').

Modern milling of wheat into flour is a process that employs grooved steel rollers. The rollers are adjusted so that the space between them is slightly narrower than the width of the wheat kernels. As the wheat is fed into the mill, the rollers flake off the bran and germ while the starch (or endosperm) is cracked into coarse pieces in the process. Through sifting, these endosperm particles, the semolina, are separated from the bran. The semolina is then ground into flour. This greatly simplifies the process of separating the endosperm from the bran and germ, as well as making it possible to separate the endosperm into different grades because the inner part of the endosperm tends to break down into smaller pieces than the outer part. Different grades of flour can thus be produced.

Semolina made from hard durum wheat (Triticum turgidum subsp. durum) is pale yellow in color. It may be milled either coarse or fine, and both are used in a wide variety of sweet and savory dishes, including many types of pasta.

Semolina made from common wheat (Triticum aestivum) is beige in color. In the United States, it is called farina (not to be confused with Italian farina, which is common-wheat flour), and it is used more often for desserts than for savory foods. On the Indian subcontinent, common-wheat semolina may be milled either coarse or fine, and both are used in a wide variety of both sweet and savory dishes. Common names in other languages include:

In the United States, meal produced from grains other than wheat may also be referred to as semolina, e.g., rice semolina and corn semolina. Corn semolina is commonly called grits in the United States.^{[citation needed]}

In Germany, Austria, Hungary, Bosnia-Herzegovina, Bulgaria, Serbia, Slovenia, Romania, Slovakia and Croatia, (durum) semolina is known as (Hartweizen-)Grieß (a word related to "grits") and is mixed with egg to make Grießknödel, which can be added to soup. The particles are fairly coarse, between 0.25 and 0.75 millimeters in diameter. It is also cooked in milk and sprinkled with chocolate to be eaten as breakfast.