The Cathedral Church of St Mel is a Catholic cathedral located in Longford, Ireland. Built between 1840 and 1856, it is considered a flagship cathedral of the Irish midlands and a landmark building.

The cathedral is dedicated to Saint Mél and was destroyed by a fire on Christmas Day 2009, but was restored and reopened in December 2014.

The Neoclassical stone building features stained glass windows and a Carrara marble altar. The restoration project cost €30 million. The cathedral is depicted on the crest of all Co Longford GAA teams and League of Ireland club Longford Town.