Saint Nicholas Church, Eastern Orthodox church building in central Sofia, Bulgaria.

Saint Nicholas Church is a small Eastern Orthodox chapel on Tsar Kaloyan Street in central Sofia, built in the 13th century by the sebastocrator Kaloyan as a family church. Its medieval walls were rebuilt and frescoed in the 1950s, and the interior preserves 20th-century icons, including a wonder-working icon of Saint Nicholas that survived the 1944 bombing.

The oldest walls beneath the church date to the 4th century, when a palace complex built under Constantine the Great stood here. After Tsar Krum took the city in 809, the surviving palace became the residence of the Bulgarian governor of the Sredets district. In the 13th century Kaloyan the sebastocrator built the family chapel of St. Nicholas on the site.

The church serves as a gathering place for devotees honoring Saint Nicholas, especially on his feast day in December. The religious traditions and the saint's name shape how locals experience this sacred space.

The church stands on Kaloyan Street behind the Rila Hotel in the city center and is easily reached on foot. Visitors should know this is an active place of worship and should show respect for the religious setting when entering.

The oldest walls under the church date from the time of Constantine the Great, the 4th century, when a palace complex stood on this spot. These Roman-era remains are preserved in the church's authentic underground walls, not above ground, so they are seen below the present floor rather than in the open air.