Firefighters were called to Coleman United Methodist Church on the 400 block of Anderson Drive in Minquadale around 4 p.m. Sunday.
Officials say the fire damaged the back of the building.
No injuries were reported.
The blaze caused an estimated $300,000 in damage to the building.
It's not clear what sparked the fire. The state fire marshal's office is investigating.
Anyone with information is asked to call (302) 323-5375.