Kirk of St Nicholas, Aberdeen, Scotland United Kingdom

The Kirk of St Nicholas is a historic church located in the city centre of Aberdeen, Scotland. It is now officially known as the "Kirk of St Nicholas (uniting)" as it is membership of both of the Church of Scotland and the United Reformed Church. It is also known as "The Mither Kirk" (mother church) of the city.

The earliest mention of a church on the site of the present Kirk can be found in a Papal document of 1157. Given Aberdeen's proximity to the sea, St Nicholas was chosen as the patron saint of Aberdeen, as a miracle attributed to him was the rescue of some sailors in a storm.

The Kirk was enlarged in the 15th century. St Nicholas and St Mary's, Dundee, were probably the largest parish churches in medieval Scotland. This work was dedicated by Bishop Elphinstone in 1498. The 500th anniversary of the dedication of the enlarged church was marked with the installation of a special stained glass window at the main entrance to the Kirk, overlooking Drum’s Aisle.

The church contains the Drum Aisle (the ancient burial-place of the Irvines of Drum Castle) and the Collison Aisle, which divide the two congregations and which formed the transepts of the 12th century church of St Nicholas (architectural detail survives from this period). The West Church was built between 1751 and 1755, to plans gifted to the burgh by James Gibbs, in the Italian style, on the site of the medieval nave, the East in 1834 in Gothic-revival style on the site of the choir. In 1874 a fire destroyed the East Church and the old central tower with its lead-clad timber spire and its fine peal of nine bells, one of which, Laurence or "Lowrie", was 4 ft (1.2 m) in diameter at the mouth, 3.5 ft (1.1 m) high and very thick. The church was rebuilt and a massive granite tower erected over the intervening aisles, a new peal of 36 bells, cast in the Netherlands, being installed to commemorate the Victorian jubilee of 1887. These were replaced in 1950 with a carillon of 48 bells, the largest in the UK.