Igreja da Sé, Roman Catholic cathedral in Sé district, Macau.

Igreja da Sé is a single-storey cathedral with a symmetrical facade of stone and two three-storey bell towers, the right one holding a black-and-white clock. The central section has three arched doorways and a round window in the pediment. Inside, pale green walls, a flat ceiling and dark wooden pews lead to an altar recess with stained glass and painted text such as "SACRIFICIUM".

A small wooden chapel stood here before 1623, when it was raised to cathedral status; the diocese had previously been based at St. Lazarus' Church. The first stone cathedral was consecrated in 1850 by Bishop Jerónimo José da Mata, then badly damaged by the 1874 typhoon. The present concrete building dates from 1937 and cost about 100,900 patacas.

Locals long called it the "Temple of the Watcher" (望人寺) because women on the slope looked toward the South Bay for husbands returning by sea; land reclamation has since hidden the water. Its Chinese nickname, 大廟 ("Great Temple"), also named the square in front, 大廟頂. The cathedral's bell, made in England, commemorates King Pedro V's accession.

The cathedral stands on Largo da Sé, the small sloping square also called Largo da Igreja da Sé, in the Sé parish of the Macau peninsula. Its main door faces north, though the earliest entrance faced southwest toward the end of Rua do Campo. The building is part of the Historic Centre of Macau World Heritage site, so it is reached on foot through the old streets.

The flat roof is not original: the 1874 typhoon destroyed the cathedral's two arched vaults, and they were never rebuilt. The clock in the right tower is English-made and commemorates the accession of King Pedro V of Portugal. The oldest side chapel, with a wooden vault, holds the Virgin of Chastity.