Glasgow Cathedral is a parish church of the Church of Scotland in Glasgow, Scotland. It is the oldest cathedral in mainland Scotland and the oldest building in Glasgow. The cathedral was the seat of the Archbishop of Glasgow, and the mother church of the Archdiocese of Glasgow and the Province of Glasgow, until the Scottish Reformation in the 16th century. Glasgow Cathedral and St Magnus Cathedral in Orkney are the only medieval cathedrals in Scotland to have survived the Reformation virtually intact. The medieval Bishop's Castle stood to the west of the cathedral until 1789. Although notionally it lies within the Townhead area of the city, the Cathedral grounds and the neighboring Necropolis are considered to be their own district within the city.

The Church of Scotland is a Presbyterian denomination of Christianity that holds the status of the national church in Scotland. It is one of the country's largest, having 259,200 members in 2023. While active membership in the church has declined significantly in recent decades, the government Scottish Household Survey found that 20% of the Scottish population, or over one million people, identified the Church of Scotland as their religious identity in 2019. The Church of Scotland's governing system is presbyterian in its approach, therefore, no one individual or group within the church has more or less influence over church matters. There is no one person who acts as the head of faith, as the church believes that role is the "Lord God's". As a proper noun, the Kirk is an informal name for the Church of Scotland used in the media and by the church itself.