In 1879, the first post office in Antigo opened as a part of the postmaster's general store. Over the years, the post office had many temporary locations. Finally in 1911, a site was purchased for a new, permanent post office. In 1916, the first federally owned and built post office opened in Antigo. It cost $60,000 to build.

The Antigo Post Office is an excellent example of a Neo-Classical Revival style building designed for a small city by the federal Supervising Architect's Office. This style is visible in the building's two-story pilasters and large cornice. Other details reflect Beaux-Arts classicism, seen in the use of large arched openings and the embellishment of the frieze. The post office is an imposing building in Antigo. It is taller than nearby commercial buildings, and the Neo-Classical design helps to portray a solid federal presence in the city.

The Antigo Post Office was constructed during a transitional period between individualized plans and the more standardized plans for post office facilities. The McAdoo classification system, implemented in 1915, specified the materials and the level of decoration appropriate for each post office. Since the land for the Antigo Post Office was purchased before this time, it is reasonable that the plans for the building were also completed before the advent of the McAdoo system, explaining the more elaborate styling and detailing.

The Antigo Post Office is open during normal business hours.