The courthouse was designed by the renowned architect firm of Holland & Squires of Topeka. Senior partner James C. Holland served as Kansas State Architect in 1895-1898. The building was completed in 1908 for just over $54,000 and is listed on the National Register of Historic Places.

 Richardsonian Romanesque is a very free Revival style that incorporates 11th-and-12th century southern French, Spanish and Italian Romanesque characteristics, which are seen in the round-headed "Romanesque" arches and recessed entrances of the building. Typical of this design is the division of the main structure above the basement level into three distinct bands: a band with windows headed by lintels; the next band up with windows headed with arches; and a distinctive separation of the roof line which includes decorative dormers, all accented with the tower built over the main entrance which features the arch supported on short columns.

One hundred cords of local Septarian concretion rock were used in the foundation, with Cowley County Cottonwood Limestone and Post Rock Limestone from Glen Elder used to build the lower and upper floors. The trim is primarily of Blue Sandstone from Warrensburg, Missouri, with some Georgian granite. The interior walls are lined with Tennessee marble. The floors are of mosaic tile. Ornate green tile fireplaces still decorate many of the county offices and steam heat is still used in part of the second floor.

Many unusual stone carvings grace the outside of the courthouse. The Lion represents the qualities of masculinity, strength, watchfulness, and courage. Medusa represents femininity, wisdom, life cycle and mortality. The face of an early settler John Wineland, "The Sidewalk Superintendent," is found on the south face of the clock tower. Wineland came every day to oversee the construction and irritated the stone masons enough that they carved his face into the rock.

The courthouse, the pride of the Solomon Valley, dominates the skyline of Osborne and in 2007 celebrated its 100th anniversary. Fundraising efforts are currently underway to raise the $50,000 needed to restore the clock to working order.