Magnolia began as a stagecoach stop along the Louisville-Nashville Turnpike about 1850. It gained its first post office in 1851 which was named after Postmaster David Harris’ wife.
After the Civil War, the post office was moved to the town of Centerpoint, but the name reverted to Magnolia.
The Old Providence Church, later Magnolia Cumberland Presbyterian Church, was built in the 1840s. Soon, several stores were established and the town began to grow. In the mid-1870s Magnolia had a population of 30. The 2010 census places the number at about 500.