is a Catholic church in Nagasaki, Japan, also known as the Church of the 26 Japanese Martyrs. It is the only western-style building declared a national treasure, and is said to be the oldest church in Japan. Designed by a French priest, Father Furet, Ōura Church was constructed under the supervision of the French priest Bernard Petijean by local builder Koyama Hidenoshin, being completed in December 1864. The original building included both Gothic and Baroque features, but after additions in 1879, the building was completely in the Gothic style. The church faces in the direction of Nishizaka Hill, where the 26 martyrs were crucified in 1597. The wooden construction, stained glass windows and the oil painting "Martyrdom of the 26 Saints" on the wall to the right are the main features of the church. The white marble statue of the Holy Mother at the entrance was built in commemoration of the dramatic discovery of the "Hidden Christians" - those who had gone underground after the Shimabara Rebellion of the 1630s. On March 17, 1865, a group of peasants from Urakami came to the church and professed their faith to Father Petijean, thus revealing that Christianity had survived through centuries of persecution. The bronze relief in the courtyard below the church shows the memorable scene of the discovery. Before long, tens of thousands of underground Christians came out of hiding in the Nagasaki area. News of this fact reached Pope Pius IX, who declared this "the miracle of the Orient."

Today, the church remains a popular place for worshippers and tourists alike, drawn to its unique, elegant European style.