Reformed Church of Notre Dame in Nyon, Reformed parish church in Nyon, Switzerland

The temple de Nyon, also called the Reformed Church of Notre-Dame, is a Protestant church in Nyon. Its oldest part, the Romanesque choir, dates from the 12th century (1175–1200), while the nave with its late Gothic vault was built between 1471 and 1481. The bell tower above the choir was rebuilt in 1935–1936, and the exterior uses different tones to mark the building's successive architectural periods.

The oldest part is the Romanesque choir, built between 1175 and 1200; the nave piers date from 1393–1394 and the Gothic vault and most side chapels from 1471–1481. The church was originally Catholic, dedicated to Notre-Dame. After Bern annexed the Pays de Vaud, the Reformation was introduced in 1537 and the building became the Reformed temple of Nyon.

The church was originally Catholic Notre-Dame; after Bern annexed the Pays de Vaud in 1537, it became the Reformed temple. Since 2016 the pews are again placed crosswise, as before 1920, centring the service on the Word. Concerts and other cultural events are also held inside.

The church is centrally located in Nyon and easy to reach on foot. Visitors should know that regular services take place, so checking visiting hours in advance is a good idea.

The oldest bell, cast in 1518 for a vanished church dedicated to the Theban Legion martyrs, was moved to the Tour de l'Horloge after the bell tower was demolished in 1795 and only returned to the tower in 1936. Its bronze crown was restored in 2013–2016. In 2016, schoolchildren carried the bells through town in a traditional procession and symbolically reinstalled them.