The Sacred Catholic Cathedral of the Immaculate Conception of the Virgin Mary, located on Fragkon Street in Thessaloniki, is a notable landmark. Built in 1899 on the site of an earlier church from 1743, this cathedral is a key location for the city’s Catholic community and serves as the seat of the Apostolic Vicariate of Thessaloniki, which administers Roman Catholic communities in northern Greece.
Designed by Vitaliano Poselli, an Italian architect invited by the Ottoman administration to modernize Thessaloniki’s infrastructure, the cathedral’s style reflects Renaissance influences and bears European architectural elements, particularly French. The building features a three-aisled basilica structure crowned with a semi-dome that leads to its side arches. The interior is adorned with Corinthian-style columns, stained glass windows, and a central altar that houses a figure of the Virgin Mary. Visitors are also drawn to the statue of Paul the Apostle.
The crypt, dedicated to the Sacred Heart of Jesus, was completed and consecrated in 1897. Financial contributions from individuals such as Frederick Charnaud, a French tobacco merchant, aided in the church's construction. The cathedral was consecrated on 3 May 1900.
Despite surviving the Great Fire of Thessaloniki in 1917, the cathedral sustained significant damage during World War II, losing its roof, furnishings, and organ. Post-war repairs restored the roof, introduced new furnishings and stained-glass windows, and replaced the organ. Subsequent renovations included relocating the altar in the early 1970s, refurbishing the crypt in 1981, repainting the church in 2000, and installing modern lighting, heating, and air-conditioning systems in 2008.
The cathedral’s schedule includes regular Mass services in both Greek and English. On Sundays, services are held at 10:00 am and 7:00 pm (or 6:00 pm during winter). Weekday services include Greek Masses on Monday, Wednesday, and Friday evenings at 7:00 pm (6:00 pm in winter), and on Tuesday, Thursday, and Saturday mornings at 8:00 am.
The Feast of the Immaculate Conception on 8 December is among the most significant Marian celebrations. The church’s welcoming schedule provides opportunities for worship and reflection, maintaining its role as a spiritual center for Thessaloniki’s Catholic residents. The Sacred Catholic Cathedral of the Immaculate Conception remains an architectural and cultural treasure within Thessaloniki, offering a distinct contrast to the city’s predominantly Paleo-Christian landmarks.