The Reformed Great Church (Dutch: Grote Kerk) is a prominent Protestant church located in the city of Haarlem, Netherlands. Originally built in the 14th century, it showcases a mix of Gothic and Renaissance architectural styles. The church is known for its impressive stained glass windows and a large organ, which is one of the oldest in the country. Historically, the Reformed Great Church played a significant role in the Reformation in the Netherlands. It became a central place of worship for the Reformed Church after the Protestant Reformation, reflecting the shift from Catholicism to Protestantism in the region. Today, it serves both as a place of worship and a cultural landmark.