TRÉGUIER, a port of western France, in the department of Cotes-du-Nord, 36 m. N.W. of St Brieuc by road. Pop. (1906), 2605. The port is situated about 5% m. from the English Channel at the confluence of two streams that form the Tréguier river; it carries on fishing and a coasting and small foreign trade. The cathedral, remarkable in having three towers over the transept, one of which is surmounted by a fine spire, dates from the 14th and 15th centuries. It contains the sumptuous modern mausoleum of St Yves (d. 1303), a canon of the cathedral, the building of which was largely due to him. To the south of the church there is a cloister (latter half of the 15th century) with graceful arcades. There is a statue of Ernest Renan, a native of the town. Saw-milling, boat-building and flax stripping are carried on, together with trade in cereals, cloth, potatoes, &c.
Tréguier (Trecorum), which dates from the 6th century, grew up round a monastery founded by St Tugdual. In the 9th century it became the seat of a bishopric, suppressed in 1790.