A rochet (/ˈrɒtʃət/) is a white vestment generally worn by Latin Catholic and Anglican bishops in choir dress. It is virtually unknown in Eastern Christianity. The rochet in its Roman form is similar to a surplice, with narrower sleeves and a hem that comes below the knee, and both may include lace. The Anglican form is a descendant of traditional albs worn by deacons and priests, but with sleeves gathered at the wrists and nearly as long as the underlying cassock.

The word stems from the Latin rochettum (from the Late Latin roccus, connected to the Old High German roch, roc and the Anglo-Saxon rocc; Dutch koorhemd, rochet, French rochet, German Rochett, Chorkleid, Italian rocchetto, Spanish roquete), which means an ecclesiastical vestment.

In the Catholic Church, cardinals, bishops and certain other dignitaries use a rochet, a garment that is worn over the cassock for non-eucharistic liturgies or Masses at which the wearer is not a celebrant.

The Catholic rochet is a tunic of white, usually fine linen or muslin (batiste, mull) reaching about to the knee, and distinguished from the surplice mainly by the narrower sleeves which make its arms tight-fitting. It is frequently trimmed with lace. The lower edge and the sleeves may also be garnished with lace, lined with violet or red silk (in the case of prelates), or, more rarely, embroidered borders.

The rochet is proper to, and distinctive of, prelates and bishops, but the right to wear it is sometimes granted by the pope to others, especially the canons of cathedral churches. It is not a vestis sacra, and thus cannot be used as a substitute for the surplice (e.g., in the administering of the Sacraments, following the Decree of the Congregation of Rites of January 10, 1852). Nonetheless, since it is used at choir services and is ordered to be worn over everyday dress at Mass (Missa rom. Rit. celebr. i. 2), it may be included among liturgical vestments in the widest sense. It is worn instead of a surplice by Canons Regular as part of their habit for liturgical use alone.

The earliest notice of the use of the rochet is found in a 9th-century inventory of vestments of the Roman clergy. In this, it is called camisia, a name which it retained at Rome until the 14th century. It seems to have been proper to particular members of the clergy by that time. Other Roman names for the vestment were succa, sucta; it was not until the 14th century that the name rochettum appeared at Rome, but it was not long before it had superseded all the native designations. In the Middle Ages, it was always plain.

Outside Rome, the vestment is met with fairly early, e.g. in the Frankish empire (9th century) as alba clericalis, in contrast to the liturgical alb, and in England (10th century) under the name of oferslip (in the 46th canon of the ecclesiastical laws of Edgar). At the beginning of the 12th century, the rochet is mentioned under the name of camisia, by Gilbert of Limerick and by Honorius, and, somewhat later, by Gerloh of Reichersperg as tunica talaris. From the 13th century onward, it is frequently mentioned. The name rocheltum is first traceable in England; in Germany and northern France, the rochet was also called sarohi (Latinized sarrotus) or sarcos (Latinized sarcotium).

Outside Rome, the rochet was, until well into the 14th century, a vestment common to all the clergy, especially to those of lower orders; and so it remained in some places as late as the 19th. Moreover, in especially in the German dioceses, it had a liturgical character, being used instead of the surplice.