Church of St Constantine and Helena, Eastern Orthodox church in Plovdiv, Bulgaria

The Church of St Constantine and Helena is a three-nave basilica in Plovdiv's Old Town, between the Hills of the Players and the Guards, next to the Hisar Kapia gate. It was rebuilt in 1832 by master builder Petko Boz of Bratsigovo. A bell tower stands in the northwest corner of the churchyard, and three Greek-inscribed tombstones from 1795–1801 lie in the open narthex.

A medieval room, likely a crypt, lies beneath the altar, and foundations of a 13th–14th-century church were found nearby. A 1578 visit by Stephan Gerlach mentions a St Constantine church here. The present church was rebuilt by Bratsigovo masons led by Petko Boz and consecrated on 30 October 1832, after Todor Petkov Moravenov raised 200,000 groschen and Valko Kurtovich Chalakov obtained a sultan's firman in 1830.

The interior displays frescoes created by two artists in the 1860s and holds icons spanning multiple periods. These artworks shape how the church looks today and tell the story of artistic tradition across generations.

The church welcomes visitors during daylight hours, with extended times in summer and shorter times in winter. Access is straightforward for those walking in the area and visitors should wear appropriate dress, especially during services.

The iconostasis was made in Vienna and blends Baroque style with gilded decoration. Artist signatures on the oldest icons reveal the hand of a notable Bulgarian painter.