The Old Post Office Block is a historic commercial building at 54-72 Hanover Street in Manchester, New Hampshire.

Built in 1876, it is a local landmark of Victorian Italianate commercial architecture, serving as the main post office, and as a newspaper publishing house for many years.

[1] The Old Post Office Block is located in Manchester's downtown business district, on the north side of Hanover Street between two other historic buildings, the Harrington-Smith Block (once home to the Strand Theater) and the Palace Theatre.

It is three stories in height, built out of brick with a projecting bracketed cornice at the top of its facade.

[2] The block was constructed in 1876, built to serve both as a post office, and as home to the presses of the Mirror newspaper.