Established by Carlisle Corporation in 1893, Tullie House Museum and Art Gallery houses considerable collections of fine and decorative art, human history and natural sciences. The museum underwent a major redevelopment in 1990, involving expansion within existing buildings and the construction of a new wing housing the new Border galleries, an Art Gallery, and shop, lecture theatre and restaurant spaces. Since this redevelopment, the City's Arts Unit has been an integral element of the service, extending its activities district-wide. In 2001 an underground gallery was developed as part of a Millennium Commission Award which showcases both Carlisle and the museum's collections.  

Tullie House incorporates the town house of that name, the origins of which can be traced back at least to the 16th century. The Tullie family and their descendants occupied the building until the 19th century.Formerly known as the White House, the house was modernised in the late 17th century under the ownership of Thomas Tullie, who was sometime Dean of Carlisle. The handsome classical façade in red and yellow sandstone, with ornate lead downspouts, bears the date of 1689. This faces onto Abbey Street.

Remaining internal features of 17th century date within the building are a large ground floor fireplace and a Jacobean oak staircase. The latter leads to wood-panelled upper rooms. A portrait hanging on the stairs shows the last private occupants, the Dixons, in the largest of these rooms - their Drawing Room - in 1842.
Late 19th century extensions in local sandstone, to the designs of C.J. Ferguson, added a range of buildings on the north side running through from Abbey Street to Castle Street. In part, this replaced some of the earlier buildings. Extensive use of tiles (by Craven Dunhill, Jackfield, Ironbridge) and Roman-inspired mosaic flooring are typical of the period. There are two elegant wrought-iron Victorian staircases inset with heraldic shields of the City of Carlisle. The historic buildings are Grade I* Listed.
 
A new range of buildings was added in 1989-90 to create new galleries and related facilities. This extended the site considerably on the north and east sides. The latest development (2000-2001) created the Carlisle Millennium Gallery, which extends below the A595 road on the north side of the site. A public walkway connecting Castle Street to the Castle Green, runs alongside this and features public artwork of high quality.