The Church of Agios Nikolaos is an Orthodox temple in Syros and a patron saint of the capital Ermoupolis.
It is near to Miaouli Square and the Apollon Theater and is considered to be one of the most important sights of the island.
It is the third most ancient temple of Ermoupolis, after the Holy Metropolis of Metamorphosis (1824) and the Holy Church of the Assumption of Virgin Mary (1828).
The majestic temple was founded by Metropolitan of the Cyclades, Daniel Kontoudes, on 28 February 1848, in plans by G. Metaxas and was officially inaugurated on 14 September 1870 by Archbishop of Syros Alexandros Lykourgos, without the completion of the interior decoration.
The temple, in the shape of a cross, is placed in a raised yard with a marble parapet and railing. It belongs to the type of basilica with a dome.