Investiture (from the Latin preposition in and verb vestire, "dress" from vestis "robe") is a formal installation or ceremony that a person undergoes, often related to membership in Christian religious institutes as well as Christian knighthoods or damehoods, in addition to government offices.

In an investiture, a person may receive an outward sign of their membership, such as their religious habit, an ecclesiastical decoration (as with chivalric orders) or a scapular (as with confraternities); they may be given the authority and regalia of a high office. Investiture can include formal dress and adornment such as robes of state or headdress, or other regalia such as a throne or seat of office. An investiture is also often part of a coronation rite or enthronement.