A trefoil (three leaf) is a graphic form composed of three leaves or lobes.
Trefoil may also refer to: Clover, or trefoil, common names for plants of the genus Trifolium Trefoil Island, an island in Australia, part of Tasmania's Trefoil Island Group Trefoil, Alberta, a locality in Special Area No. 2, Alberta, Canada Trefoil knot, the simplest example of a nontrivial knot Trefoil, a variation of the card game La Belle Lucie Trefoils, a variety of Girl Scout cookie Trefoil-class concrete barge, an American Type B ship
, a Union Navy steamer
See also
Quatrefoil (disambiguation) (four leaf) Cinquefoil (disambiguation) (five leaf) Lotus (genus), flowering plants that include species with common names including "trefoil" Trefoil Guild, part of Girlguiding Vertical trefoil and oblique trefoil, Zernike polynomials Trefoil knot fold, a protein fold