Third Onondaga County courthouse

The third Onondaga County courthouse stood in Clinton Square, Syracuse, New York, from 1858 to 1968. Designed by Horatio Nelson White in the Italianate architectural style, the building functioned as a courthouse until 1907. After another courthouse superseded it, the building held various governmental offices for about fifty years.

The Onondaga County court was moved from its initial building in the town of Onondaga Hill to a courthouse between Salina and Syracuse in the first half of the 19th century. After the second courthouse burnt down in 1856, White, at the time the best-known Syracuse architect, was hired to design a new building, this time located in downtown Syracuse. The courthouse was made from hand-cut Onondaga Limestone and dedicated in early 1858. Despite renovations into the 1870s, by the turn of the century the building was run-down and a new courthouse was built to replace it. After the court was relocated in 1907, the building held the Syracuse Board of Education until 1945, and several other organizations including the Syracuse Police Department into the 1960s.

By the 1960s, the building was largely unoccupied and at threat of demolition. Despite proposals to repurpose the building in various ways, including in the book Architecture Worth Saving in Onondaga County, it was demolished in 1968. The stones that made up the top 36 or 37 feet (11 or 11 m) of the courthouse's 80 feet (24 m) tall tower were preserved and as of 2022 are held unassembled at the Syracuse Hancock International Airport.