The market is located on the edge of the former lake shore, and the elevation drops over 10 feet (3.0 m) between the north and south ends.

Opened in 1979, the Market Gallery offers changing exhibitions dedicated to Toronto's history, art and culture, and programs for school and community groups.

Lane incorporated into his design contrasting red brick and white stone in the Georgian architecture tradition.

Two-storey wings extended on either side of a three-story center block and housed the offices of city staff and shops on the ground floor.

The centre block contained the Council Chambers, Toronto Police Station # 1 and a jail in the basement.

The City Hall was renovated in 1851 by William Thomas, with new shops in the wings, keystones in the arched windows and improvements to the police station and jail cells (which were reportedly subject to flooding).

The new steel truss roof was proposed to cover the entire building structure, allowing more open space with a high ceiling and more natural light.

Time and Place, a citizens' group, proposed a renovation and that the former Council Chamber be converted into a "City display space."

The renovations lasted from 1974 to 1978 and included the opening up of the basement for retail use, a new floor for the main level, installation of a freight elevator and new doors to accommodate increased pedestrian traffic.

The renovated Council Chambers opened as the Market Gallery, an exhibition facility to showcase the City's extensive archival and art collections, on March 7, 1979.