The Church of St Martin is an ancient Church of England parish church in Canterbury, England, situated slightly beyond the city centre. It is recognised as the oldest church building in Britain still in use as a church, and the oldest existing parish church in the English-speaking world, although Roman and Celtic churches had existed for centuries. The church is, along with Canterbury Cathedral and St Augustine's Abbey, part of a World Heritage Site.

Since 1668 the church has been part of the benefice of St Martin and St Paul Canterbury. Both St Martin's and nearby St Paul's churches are used for weekly services. The current rector of the parish is the Reverend Mark Richard Griffin.