Clonsilla is one of those well known locations on the Midland Great Western Railway's Dublin to Sligo line. Clonsilla, which is now very much on the outer suburban fringe of Dublin city, was original closed in 1947, but reopened in 1981 with the introduction of the new commuter service to Maynooth, by which time most of the original station buildings had been demolished. Clonsilla was also the junction of the 1862 built Dublin & Meath rail line, which diverged just west of the station and headed north to Navan. Passenger services on the Navan line ceased in 1947, but the line remained in use for occasional goods traffic until 1963, when the line was lifted.

It wasn't until the introduction of the new 2600 'Arrow' railcars in the mid 1990s, that the Maynooth commuter service really began to take off, and as a result the line between Clonsilla and Maynooth was re-doubled between 1999 & 2000, having been singled by the Great Southern Railway way back in 1929. This also brought about upgrading of the signalling and stations on the line, however due to the busy level crossing at Clonsilla Station, the typical MGWR signal cabin survives, and still controls the crossing gates. Part of the already mentioned closed Navan line is to be reopened by 2012, and work has already begun on the line to Dunboyne.