Lincoln Museum, formerly The Collection, is the county museum and gallery for Lincolnshire in England. It is an amalgamation of the Usher Gallery and the City and County Museum. The museum part of the enterprise is housed in a new, purpose-built building close by the Usher Gallery in the city of Lincoln. The name "The Collection" was in use from 2005; it was renamed "Lincoln Museum and Usher Gallery" in 2023.

Lincoln Museum has existed since 2005. It is a merger between the Usher Gallery, which was established in 1927, and the City and County Museum, founded in 1906. The first curator of the Lincoln City and County Museum was Arthur Smith (1869–1947), who was born in Leicester and raised in Grimsby, and who was interested in natural history. After being appointed curator, he moved to Lincoln. He became the (honorary) secretary of the Lincolnshire Naturalists' Union (LNU) and acquired important collections, for example from J. E. Mason (Heteroptera, bugs), W. Wallace (Diptera, flies) and G. W. Mason (Lepidoptera, butterflies). The museum also acquired important collections of bird specimens, for instance from George Henry Caton Haigh.

Smith retired as curator in 1935. He moved away from Lincoln and died in 1947.

Lincoln consists of two parts, that at the top of the cliff and that in the Witham valley. The site of the museum is on the steep slope between the two and within the Roman colonia which linked the 1st-century legionary fortress with the shipping and commerce in the river.

The Usher Gallery was built to house the collection of James Ward Usher, using funds he bequeathed for the purpose. It was designed by the architect Sir Reginald Blomfield and was officially opened on 25 May 1927 by the Prince of Wales. It is a simple building faced in stone with brick panels separated by simplified Tuscan pilasters, above which is a frieze decorated with triglyphs and a roofline finished with a balustrade. The portico, central in the south façade, is topped by a broken pediment and urn finials. The gallery stands in a small park on the hillside looking southwards across the lower town.

The Usher Gallery is the only purpose-built public art gallery in Lincolnshire. and a Grade II* listed building. The Usher is owned by Lincoln City Council but is leased to Lincolnshire County Council.

Following an architectural design competition managed by RIBA Competitions, Panter Hudspith Architects, led by Simon Hudspith, designed the new building. It was opened in October 2005 after much work, which included an archaeological excavation. Despite the building having been designed to rest above the Roman horizon, at the foot of the pit for the lift shaft was found the corner of a mosaic-paved passage which had been laid around a courtyard.

Much of the new building is faced and paved with Ancaster stone and borrows the concept of the glass-covered courtyard from the British Museum in a feature reminiscent of a medieval alley.^{[citation needed]}