Monto was the nickname for the one-time red light district in Dublin, the capital of Ireland. Monto was roughly the area bounded by Talbot Street, Amiens Street, Gardiner Street and Seán McDermott Street (formerly Gloucester Street). The name is derived from Montgomery Street (now called Foley Street), which runs parallel to the lower end of Talbot Street towards what is now Connolly Station. It was immortalised as "Nighttown" in the "Circe" chapter of James Joyce's famous work, Ulysses, where the central protagonists Leopold Bloom and Stephen Dedalus together visit a brothel.
In its heyday from the 1860s - 1920s, there were anything up to 1,600 prostitutes working there at any one time, with all classes of customers catered for. It was reputed to be the biggest red light district in Europe at the time. Its financial viability was aided by the number of British Army barracks and hence soldiers in the city, notably the Royal Barracks (later Collins Barracks and now one of the locations of Ireland's National Museum).
The then Prince of Wales, Prince Albert Edward (later King Edward VII), according to popular legend, lost his virginity there. In the 1880s the Prince, accompanied by his wife Alexandra and their son Albert Victor, Duke of Clarence strolled unrecognised through the area, having slipped away from their bodyguards and walked through Dublin.
Between 1923 and 1925, religious missions led by Frank Duff of the Legion of Mary, a Roman Catholic organisation, and Fr. R.S. Devane worked to close down the brothels. They received the co-operation of Dublin Police Commissioner, General William Murphy, and the campaign ended with 120 arrests and the closure of the brothels following a police raid on 12 March 1925, its financial viability having already been seriously undermined by the withdrawal of soldiers from the city following the Anglo-Irish Treaty (December 1921) and the establishment of the Irish Free State (6 December 1922).
There is also an Irish folk song, Monto (Take Her Up To Monto), written by George Desmond Hodnett and popularised by The Dubliners. Monto is also twice mentioned in the Irish folk song Waxies' Dargle. Monto, Frank Duff, and the L.O.M. are also mentioned in the Peter Yeates song "Honor Bright", the story of the 1925 murder of a prostitute (Lizzie O'Neil) who used the pseudonym "Honour Bright".
- Story of Monto (Mercier mini book) by John Finegan (Author), Mercier Press (Feb 1978) ISBN 0-85342-515-9
- Monto: Madams, Murder and Black Coddle by Terry Fagan and the North Inner City Folklore Project (2000) 
- Sex in the City: The Prostitution Racket in Ireland by Paul Reynolds (Author), Pan (7 Nov 2003) ISBN 978-0-7171-3688-9
- Prostitution and Irish Society, 1800-1940 by Maria Luddy, Cambridge University Press (Nov 2007) ISBN 978-0-521-70905-7
- Madams and Murder
- The miracle of Monto? A chequered history, from prostitution to pilgrimages
- Dublin Folklore - Monto Stories from Dublin, James Joyce, Night Town,Ireland Researched by Terry Fagan, historian and tour guide.
- Montgomery Street , Dublin (Irish Place and Street Names)
- Dublin brothel faces bulldozer (2003)
- "Abandoned Women and Bad Characters": prostitution in nineteenth-century Ireland by Maria LUDDY, Journal Article (1997) (PDF)
- An Outcast Community: the "wrens" of the Curragh by Maria LUDDY, Journal Article (1992) (PDF)
- Armstrong, Maggie (14 June 2011). "The Bloomsday world tourists never get to hear about". Irish Independent. Retrieved 15 December 2012.
- Read Ireland Book Review - Issue 126
- An Phoblacht/Republican News
- The history of Dublin's old Red Light district