The Aa-kerk (also: A-kerk) is a historic former parish church in the centre of Groningen, and a dominant feature in the skyline of the city together with the nearby Martinitoren.

The chapel was situated close to the river Aa, where bargees cast off vessels in the western harbour (Westerhaven).

At this time, Groningen consisted of two centres, each surrounding a religious edifice, the Church of Our Lady at the river Aa being one of them.

Both the interior and exterior have been altered many times over the course of history due to the iconoclasm during the Reformation, war damage (Siege of Groningen) and natural phenomena (lightning strike).

[1] Images of the Siege of Groningen in 1672 show the Aa-kerk without the top of the tower.