Mount Street is one of the oldest and most historic streets in Mullingar. It was part of the original streetscape of the town when Mullingar was founded by the Normans more than 800 years ago.  The Norman Lord of Mullingar, William Petit, built his castle just south of Mount Street where the County Buildings now stand. The name “Mount” actually refers to the castle-which was  called “Petit’s Castle; the “Great Castle or “the Mount.”The castle stood for more than five centuries and housed the first military base and the first church in the history of the town.

The Courthouse at the southern end of Mount Street dates back to 1824.As well as housing the courts, the building also served as a meeting place for Mullingar Town Commission and for Westmeath County Council in the nineteenth and early twentieth centuries. The very first meeting of the Town Commission was held there in 1856 and the County Council held meetings there until the County Buildings opened in 1912. Election results were announced from the Courthouse for many years. In 1857 there was a major riot on Mount Street between supporters of rival election candidates.There was another riot in 1899 when Nationalist politicians decided to defy British authority and raise the  Irish flag on the Courthouse. Those tried in the Courthouse for political offences included Westmeath MPLarry Ginnell in 1918, Westmeath Ladies Land League President, Mary  O Connor, in 1882, and Land League founder member and Westmeath MP, Tim Harrington in 1883.

The first police station in Mullingar was in Mount Street. The Royal Irish Constabulary Barracks was located on the west side of the street across from the courthouse from the 1830s to the 1850s.

The novelist James Joyce came to Mullingar in 1900 with his father, who was doing work for the County Council. Joyce and his father worked in the Courthouse and may have stayed in lodgings on Mount Street. They had meals in a pub called Connellan’s, which stood where Caffreys’ Bar is now. Joyce probably posted letters in the post box on the wall of what is now Wallaces’ pub. The post box there dates back to Victorian times. Joyce returned to Mullingar with his father in 1901. He never forgot the town-which features in nearly all his writings. Connellans’ Bar used to have large advertisements for “Teas, Teas, Teas!”. In “Ulysses”, Joyce simply transposed the advertisement to the window of a Dublin shop. Joyce would have walked up and down Mount Street every day he was in Mullingar.

The cultural organisation, Comhalthas Ceolteoiri Eireann was founded at a meeting in the Midland Hotel in Mount Street in 1951. The first All Ireland Fleadh was held in Mullingar later that year and Mount Street was one of the venues for events during the Fleadh Ceoil na hEireann of 1963, which was held in Mullingar. The Midlands Regional Headquarters of Comhalthas opened in part of the County Buildings at the southern end of Mount Street in 2010.

The Norman Castle was demolished in the eighteenth century and replaced by the County Jail, which opened in 1789 and closed in 1900. Up until 1868, when public executions were stopped, crowds would gather weekly in Mount Street to get a good view of the hangings carried out in the jail. On one occasion, ten men were hanged in one week. A tunnel under the road connected the jail and the courthouse. The 19th-century novelist, William Carleton, who worked as a teacher in Mullingar between 1822 and 1824, was briefly imprisoned for debt in the jail in 1824.

A ghost is said to appear at the window of a building on the west side of Mount Street. Tradition says that the ghost is that of a person who was watching a hanging from the window when the window sash fell down and killed him.

Among those hanged in the jail was Bryan Seery, a tenant farmer from Castletown Geoghegan, who was executed in 1846 for the attempted murder of his former landlord, Sir Francis Hopkins. There were strong doubts about Seery’s guilt and those who called for him to be reprieved included Charles Dickens and Daniel O Connell. In 1920, Mullingar Town Commission re-named Mount Street “Seery Street” in his memory. In Irish, the street is “Sraid Seery.”

Part of Mount Street was also once known as Sterne Street-named after a relative of the 18th-century Irish novelist Lawrence Sterne, who lived in Mullingar for a short time as a boy.

The jail was demolished in 1910 and the new County Buildings and County Hall opened in 1913. Numerous stars of theatre and music have appeared in the Mullingar Arts Centre – which was known until 1998 as the County Hall. Among those to appear on the stage were Cyril Cusack, Maureen Potter, Joe Dolan, Ray McAnally and the Nobel Prize-winning playwright, Harold Pinter. New County Buildings opened in 2009 behind the original buildings. Some parts of the old jail still survive-including the Governor’s House and parts of the walls. The first vocational or technical school in Mullingar was situated in the Governor’s House. In 1915, it was proudly announced that the school now had a typewriter.

Many of the shops on Mount Street have been in business for forty years or more.These include Frayne’s, the Roma Cafe, Topic Newsagents and Caffreys’ Bar. In the Sixties, Seventies and Eighties, “Larry Caffrey’s Singing Lounge”, was one of the major entertainment venues in Mullingar. Mick Foster of Foster & Allen played there early on in his career. What is now Chambers Bar is the latest in a long line of pubs located in that building going back to at least 1911.