As of 2021, how many cathedrals in the United Kingdom have three spires?

There are only three cathedrals in the United Kingdom with three spires. Lichfield Cathedral, dating from the 13th and early 14th centuries is the only medieval cathedral. Both Truro Cathedral, Cornwall (late 19th–early 20th century) and St Mary's Episcopal Cathedral, Edinburgh (late 19th century) were built in the Gothic Revival style and also have three spires. Between the 14th and 16th centuries Lincoln Cathedral also had three spires and was the tallest building in the world for 238 years until the central spire collapsed in 1549 and was not rebuilt.

Lichfield Cathedral in Lichfield, Staffordshire, England is dedicated to St Chad and Saint Mary. The cathedral dates from various periods in 13th and early 14th centuries, although this can not be allocated to fixed years, since the archives were destroyed during the English Civil War.

The Cathedral of the Blessed Virgin Mary, Truro is a Church of England cathedral in the city of Truro, Cornwall. It was built between 1880 and 1910 to a Gothic Revival design by John Loughborough Pearson on the site of the parish church of St Mary.

St Mary's Cathedral (Scottish Gaelic: Cathair-eaglais Naomh Moire) or the Cathedral Church of Saint Mary the Virgin is a cathedral of the Scottish Episcopal Church in Edinburgh, Scotland. It was built in the late 19th century in the West End of Edinburgh's New Town.