St Martin's Church, Arlon, Gothic Revival church building in Arlon, Belgium.

St Martin's Church is a Gothic Revival church of tan and grey stone in Arlon, built 1907–1914 to plans by Édouard Van Gheluwe, continued by Modeste de Noyette. A single tower with clock faces and a pointed spire rises on the left of the front; the gabled body carries a circular window and a small turret. Inside, clustered columns support pointed arches and a ribbed vault painted ochre, with wooden chairs in two blocks along a tiled central aisle and an altar below a rose window and three lancets.

The present church replaced an ancient Church of St Martin and was built over seven years, from 1907 to 1914. It was designed by Édouard Van Gheluwe, who died in 1906, and completed by Modeste de Noyette. Local historians such as Jean-Marie Triffaux dispute the claim that King Leopold II initiated the project as a monumental boundary marker.

The church is dedicated to Saint Martin, and its origins trace back to an older Church of St. Martin founded in Arlon in his honour. Since 2002 it has been listed as major heritage of Wallonia, and the whole building except the organ is classed as exceptional heritage of the Walloon Region. The dean has been Abbot Pascal Roger since September 2020.

The church stands in Arlon, in the Belgian province of Luxembourg. Its 97-metre tower, the tallest ecclesiastical building in Wallonia, makes it a landmark visible from much of the town. Full restoration began in 2012 and was still under way in 2024, including renewal of the crossing spire, so parts of the building may be under scaffolding.

The tower reaches 97 metres, making it the tallest ecclesiastical building in Wallonia and one of Belgium's ten highest church towers. A full restoration begun in 2012, still under way in 2024, includes renewing the spire over the crossing.