Mount Mourne is an unincorporated community in Iredell County, North Carolina, United States. Mount Mourne is located on North Carolina Highway 115, 3.5 miles southwest of Mooresville. The Mount Mourne post office was originally established on April 5, 1805 with James Houston as postmaster. It has been in continuous operation since 1805 and currently has a ZIP code of 28123. The community was named by early settlers after Mourne Mountains in Northern Ireland.