County Hall is a former municipal building, now used for student accommodation, in Hobson Street, Cambridge, Cambridgeshire, England.

[4][5][6] The new building, designed by Herbert Henry Dunn in the neoclassical style,[7] was formally opened by Sir George Fordham, the chairman of the county council, on 5 February 1914.

[8] The design involved a symmetrical main frontage with seven bays facing Hobson Street with the end bays slightly projected forwards; there were round-headed windows on the ground floor and sash windows on the first and second floors interspersed with tall Ionic order columns which supported an entablature carved with the words "County Hall 1913".

[9] By the late 1920s the county council had also found the Hobson Street building too small and chose to move to the shire hall at Castle Hill in 1933.

[12] The conversion works included the installation of a smoked-glass drum containing a spiral staircase to provide additional access for students[13] and alterations to the rooms on the second floor to create a lecture theatre which was named the Plumb Auditorium, after Sir John Plumb, a historian.