Based in Weston Park, the museum opened in 1875, and contains collections of decorative arts, human history, natural history and visual arts. The building is Grade II* listed.

The public art gallery was added in 1887 following an art bequest from Rotherham businessman John Newton Mappin. It was designed in a neo-classical style by local practice Flockton & Gibbs and was later bombed during the Second World War.

The museum building was in poor condition and needed improvement, particularly to its accessibility and display of collections. The project saw a restoration and enhancement of the museum and gallery, which reopened as Western Park Museum. 

New permanent exhibitions were constructed, with the creation of enhanced temporary exhibition spaces. Collections will be better presented and conserved with off-site storage.

A learning centre was designed to be used by the local community, plus a resource centre to help visitors access more of the collections.

Improved space, facilities and access also boosted the visitor experience, and access was enhanced to Weston Park.

The Weston Park Museum won The Guardian's Family Friendly Museum Award in 2008.