The oldest part of Janakkala Church is believed to be built in the end of the 15th century or in the beginning of the 16th century. It was dedicated to St. Lawrence probably in 1520. It was originally oblong in shape, but was enlarged in 1839-1840, and remodeled using a cruciform plan in 1848-1849. The church has been restored several times. The present belfry was built in 1784.