Kirk is a Scottish and former Northern English word meaning 'church'. The term the Kirk is often used informally to refer specifically to the Church of Scotland, the Scottish national church which developed from the 16th-century Reformation. Many place names and personal names are derived from kirk.

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.