
The ground floor of the Mansion House contains several rooms whose purpose was severely practical. To the left of the front door lie the two committee rooms. Probably this room was originally used for the twice-weekly magistrates court for the borough. Round the large oval committee table are many of the set of mahogany dining chairs made by William Lilley (about 1735- 1816) of Doncaster. The entire set of twenty-seven was made in 1806 for the new dining room and cost £66. 60p. On the wall is one of three clocks made by George Hallifax (about 1726 -1811), two of them especially for the Mansion House. Hallifax was a migrant from a clock-making family in Barnsley and admitted as a freeman of Doncaster in 1750. As a condition of his admission as a freeman, the corporation ordered him to make a watch to the value of seven guineas (£7.35p) for the Mansion House. In June 1770, the corporation ordered another from him for the great kitchen. He became a councillor in 1755, an alderman fifteen years later and mayor in 1775 and again in 1791.
By the fireplace hang the town-twinning agreements between Doncaster and its American and European twins, Avion, Gliwice, Herten and Wilmington. On the wall opposite, not in view, hang photographs of the mayors of Doncaster Metropolitan Borough. The portraits of the mayors of the former County Borough of Doncaster from 1835 to 1974, which were formerly on display in the Mansion House, are now to be found at Doncaster Archives.