The Chapel of Saint Helena is a 12th-century Armenian church in the lower level of the Church of the Holy Sepulcher in Jerusalem.

In the south east of the chapel there is a chair which was reputed to be a seat that was sat in by Saint Helena, the mother of the Emperor Constantine when she was looking for the True Cross. There are two apses in the church, one dedicated to Saint Helena and one to the penitent thief on the cross. The chapel is modestly adorned in memory of Saint Helena's simplicity.

The chronicler William of Tyre reports on the renovation of the Church of the Holy Sepulcher in the mid-12th century. The crusaders investigated the eastern ruins on the site, occasionally excavating through the rubble, and while attempting to reach the cistern where the True Cross was believed to have been found, they discovered part of the original ground level of Hadrian's temple enclosure; they decided to transform this space into a chapel dedicated to Helena, widening their original excavation tunnel into a proper staircase.

During 1973–1978 restoration works and excavations were made on the Holy Sepulchre To the east of the Chapel of St. Helena, the excavators discovered a void containing a 2nd-century drawing of a roman ship, two low walls which supported the platform of Hadrian's 2nd-century temple, and a higher 4th century wall built to support Constantine's basilica; the Armenian authorities have recently converted this archaeological space into the Chapel of Saint Vartan, and created an artificial walkway over the quarry on the north of the chapel, so that the new Chapel could be accessed (by permission) from the Chapel of St. Helena.

The Church of the Holy Sepulchre

The Church of the Holy Sepulchre, also called the Basilica of the Holy Sepulchre, or the Church of the Resurrection by Eastern Christians, is a church within the Christian Quarter of the walled Old City of Jerusalem. It is a few steps away from the Muristan.

The site is venerated as Golgotha (the Hill of Calvary), where Jesus was crucified, and is said also to contain the place where Jesus was buried (the Sepulchre). The church has been a paramount – and for many Christians the most important – pilgrimage destination since at least the 4th century, as the purported site of the resurrection of Jesus. Today it also serves as the headquarters of the Greek Orthodox Patriarch of Jerusalem, while control of the building is shared between several Christian churches and secular entities in complicated arrangements essentially unchanged for centuries. Today, the church is home to branches of Eastern Orthodoxy and Oriental Orthodoxy as well as to Roman Catholicism.