The Church of Sts. Constantine and Helena (tr. Sveti Konstantin-Elena Kilisesi, bg. Св. св. Константин и Елена) is one of the two churches of the Bulgarian Orthodox Church located in Edirne. The second church of this rite in the city is St. George's Church. The Church of Saints Constantine and Helena was built in 1869, in an astonishingly short period of just seven months. The temple was funded by Bulgarians from the regions of Macedonia and Thrace.

The Bulgarian Patriarchate is the oldest Slavic Orthodox Church, with some 8 million believers. It was recognised as an independent Church by the Patriarchate of Constantinople in 927 CE. The patrons of the church in Edirne are: the Roman emperor Constantine, the saint of the Orthodox Church, and his mother Helena, considered a saint both in the Catholic and the Orthodox Churches.

The building is a perfect example of the Orthodox architecture of the period. It is a three-nave pseudo-basilica, which means that its central nave only slightly higher than the two aisles and it has a single pitched roof covering all three. The area of ​​the building is about 600 square meters. The walls were erected from stones, and two colonnades support the roof from the inside.

In 1888, the metropolitan bishop of Edirne Bulgarian Orthodox community, Ewstatij, was buried in the eastern nave of the church. His tombstone was moved near the main entrance of the building during renovation in 2008.

After the Second Balkan War in 1913, the Bulgarians were exiled from the Turkish region of Thrace, and as a result the church was abandoned and began to fall into ruin. Only in 2006, a Turkish-Bulgarian agreement was reached to renovate the temple. After many years of neglect, in 2008, the church underwent a thorough refurbishment, partly financed by the Bulgarian government.

The Bulgarian authorities donated 400,000 euros for renovations and 70,000 extra leva for the iconostasis, i.e. a wall of icons and religious paintings, separating the nave from the sanctuary. The iconostasis in the church of Sts. Constantine and Helen is decorated with 74 icons. It was created on the basis of photographs of the original iconostasis made in the 1930s.

Several historical inscriptions were discovered during reconstruction works. One of them commemorates the days of the Russian-Turkish war (1877-1878) when Edirne was captured by the Russians. The Russian text of the inscription proclaims "Toward the Brotherhood Memory, from the Russians to the Bulgarians, September 1878". This inscription is currently placed over the eastern entrance to the church yard. At the entrance to the church, on the western side of the building, there is an inscription in Bulgarian, commemorating the dedication of the church in 1869.

On 14 September 2008, the church was re-inaugurated for the faithful. The Patriarch of Bulgaria, Neofit, attended the celebrations together with the representatives of the authorities of both countries: the Bulgarian Prime Minister Sergey Staniszew and the Turkish Minister of Tourism Gunay Ertuğrul. After the speeches and prayers, the participants planted trees in the garden belonging to the church.