St Thomas' Church is a Church of England church in Garstang, a market town in Lancashire, England. It is an active Church of England parish church in the Diocese of Blackburn and the archdeaconry of Lancaster. The church was built in 1770 as a chapel of ease to St Helen's Church in nearby Kirkland and was later assigned its own parish. It is recorded in the National Heritage List for England as a designated Grade II listed building.