This is one of the earliest buildings in the village of Newboro. There is some dispute over the date of construction for this building, but it was reportedly built in 1840, while the property was owned by Benjamin Tett. Some school reports show that it was constructed in 1846. Other records show that John Kilbourn purchased the lot in 1851 from Tett and then petitioned and received money to build a public school at 10 Brock Street.

In any case, this charming building started its life as a school and was used as such for 40 years; the remains of separate entrances for boys and girls can still be seen on the front façade. In 1887, a large 2-storey brick school was built on Carleton Street. At that time, the Newboro Public School Board sold this property to the Corporation of the Municipality of Newboro to be used as a municipal office, town hall and courthouse. The classroom was converted to court chambers and jail cells were added at the rear. One of the original wooden jail doors is still visible.

The building was used as a courthouse until the early 1940s. In 1967 the Newboro Council modernized the building with paint, lighting, heating and water. Since 1998, it has served as the Newboro Branch of the Rideau Lakes Public Library.

The Newboro Courthouse is a simple rectangular structure of 1 storey built of stone, then stuccoed. The stucco has now been removed. It has no basement but has a foundation directly on Cambrian sandstone. A symmetrical set of 12-over-12 windows on each side of the original structure provided adequate light to the school room. A single brick chimney was centrally located on the low-pitch roof to accommodate stove heating by wood fire. The rear extension, also of stone, once had a door on the south façade. The interior is a large, uninterrupted room. A connecting doorway to the rear section has been made through a thick wall. This centrally-located Courthouse is a testimony to the growth and prosperity of the village.