The Westmeath County Infirmary was originally opened in 1771. Its designer is uncertain but it is similar in scale to the, now demolished, County Infirmary in Longford (1767). Both buildings consisted of simple two-storey repetitive bays unlike the more common three-storey response as for example in Navan, the grander four-storey building of Armagh or five-storey over basement building of Waterford County Infirmary.

The western bay is a later addition, possibly 1860-80s. It is most probably the domestic quarters for the surgeon and his family. There is little evidence of this change remaining other than chimney positions, thickness of old gable wall, cornices and shutter detail. Extensive remodeling was carried out around this time (Padraic O’Farrell, The Book of Mullingar) works included the removal of the entrance flagstones for tiles and the windows may have been altered at this time.

The building appears to have survived changed practices and consideration for fever wards in the 1830’s when many county infirmaries were altered or abandoned. From the minutes of the hospital the roof appears to have been in constant need of repair and a new boiler was fitted around this time. It was also noted that the boundary walls required repair and were collapsing.

 A new operating theatre was erected to the rear of the building in 1909. The 2 No. rear two-storey toilet blocks are later in construction than the theatre, possibly dating from 1912. The windows have brick surround detail and differ from the existing window style. The infirmary operations ceased on this site and moved to the new County Hospital upon its completion in 1936. Between 1940-46 the premises was used as a Fort Brigade Headquarters with various army huts constructed on site. A flagpole was constructed to front and a security hut/gate lodge constructed to entrance. From 1946 onwards the premises was controlled by Westmeath County Council, first shortly after the army left as the county engineers office and later in 1960 when the Longford Westmeath Library was established as its headquarters

The Civil Defence used part of the building between 1957 and the 1970s.

Its current owner, Dr. Paula Donnelly, with the help of her father Mr. Patsy Donnelly has restored the building and maintained original features. The Building now houses a state of the art medical facility, Bellview Clinic, and neighbouring Pharmacy.