It follows a large fire that destroyed the local post office office in the town last month.
Customers in the area had been availing of services at An Post offices in Castlemartyr and Carrigtwohill.
The new office will open at 59 Main Street, a short distance from the original office.
An Post have thanked customers in Midleton and have paid tribute to Postmaster Jessie Moran for her commitment to restoring the local service.