The Mandarin orange is a small citrus tree (Citrus reticulata) with fruit resembling the orange. The fruit is oblate, rather than spherical, and roughly resembles a pumpkin in shape. Mandarin oranges are usually eaten plain or in fruit salads. Varieties of mandarin orange include the tangerine, clementine, dancy, tangor , satsuma and several new varieties recently released by UCR such as the Goldnugget.

In some varieties, notably the tangerine, the rind is loose and can easily be removed by hand. The tangor, also called a temple orange, is a cross between a mandarin and an orange. Its thin rind is also easy to peel, and its pale orange pulp is spicy, full-flavored, and tart. Most canned mandarin oranges are satsumas.

Citrus fruit varieties are usually self-fertile (needing the bee only to move pollen within the same flower), or parthenocarpic, not needing pollination and therefore seedless. Tangerine blossoms are an exception. They are self sterile, therefore must have a pollenizer variety to supply pollen, and a high bee population to make a good crop.