The Parisi were a British Celtic tribe located somewhere within the present-day East Riding of Yorkshire, in England, known from a single brief reference by Ptolemy in his Geographica of about AD 150. Many writers have connected them with the archaeological Arras culture and some with the more securely-known Parisii of Gaul.
The Parisi are known from a description in Ptolemy's Geographica (Geographica II, 3, 10) which locates them to near Opportunum Sinus ("Good harbour"). Ptolemy is presumed never to have visited Roman Britain, compiling his work from existing sources, probably in Alexandria.
The tribe are inferred to have been surrounded by the Brigantes, and with the Coritani south of them across the Humber. Ptolemy mentions the Parisi in association with Petvaria, a town thought to be located close to Brough, East Riding of Yorkshire. Ptolemy also mentions a promontory Promontarium Ocellum, which may be either Spurn Head or Flamborough Head.
The translation and interpretation of Ptomemy's work has not been consistent over time, with differing interpretations creating potential contradictions in the spatial relationship between Opportunum Sinus and Petuaria. A more recent interpretation (2005) places both the Parisi and Petuaria on the Opportunum Sinus which leads to the common interpretation of Opportunum Sinus to be impossible geographically - an alternative feature - the inlet near Brough to Walling Fen has been suggested.
The Parisi are also mentioned in the forgery De Situ Britanniae originally credited to Richard of Cirencester (14th century AD): the Parisi's towns supposedly included Petuaria and a place Portus Felix, the locations of which were uncertain, and subject to speculation in the 19th century.