The 1908 courthouse is a gray limestone ashlar three-story Neo-Classical building with an octagonal, stained-glass, lantern dome, which becomes an internally-illuminated, greenish beacon at night. The architect of the Oneida courthouse, Christ H. Tegen, also designed the Manitowoc County Courthouse, built in 1906.

The third-floor, east stairhall contains a mural dated 1919 and painted by "F. Biberstein". It depicts a lumberman rolling on and directing floating logs - an ode to the History of Rhinelander. Across the light well, on the west wall, is a small mural depicting the "Hodag," a mythical monster of local legend.

A self guided walking tour of the historic courthouse is available.