Agios Nikolaos, Byzantine church in Chalandri, Greece.

Agios Nikolaos is a Byzantine church in Chalandri that features traditional domed structures, solid stone walls, and ornamental details typical of the style. The building's layout and construction reflect the religious and architectural standards of its period.

Agios Nikolaos was founded in 1862 on Eleftheroton Square, the central square of Chalandri, and has been the town's cathedral church since. Numerous supplementary works have been carried out on the building in the decades since its foundation. It is dedicated to Saint Nicholas and also commemorates Saints Constantine and Helen.

The church serves as a spiritual center for the Orthodox community in Chalandri, where residents gather for religious ceremonies throughout the year. It plays a meaningful role in the local religious identity and practice.

The main entrance is on the western side of the building, and visitors should wear respectful clothing since it functions as an active place of worship. It helps to check opening times in advance and observe quiet behavior during any religious services.

The church honours two feast days: Saint Nicholas on 6 December and Saints Constantine and Helen on 21 May. It was founded in 1862 on Eleftheroton Square, and further building work has continued since, so the present structure mixes phases rather than one period.