Clover or trefoil are the common names for plants belonging to the genus Trifolium. This genus consists of around 300 species of plants that are part of leguminous pea family of Fabaceae. The plant is found in many places. The greatest variety of species is found in temperate climates in the Northern Hemisphere. However, many species exist in Africa and South America, also in tropical areas on high altitude.

Various varieties of clover are widely cultivated to serve as animal fodder. The most popular clover in this respect are the white clover Trifolium repens and the red clover Trifolium pratense.