The Glasnevin we know today began to take shape with its amalgamation with the city of Dublin by Act of Parliament in 1900 and later the foundation of the parish and Church - Our Lady of Dolours in 1912. In response to the city's overcrowding of tenement houses and problems with slums, the government took action by knocking these down and relocating families to neighbouring areas of Glasnevin such as Cabra and later, Finglas, during the 1940's and 50's. The area was facilitated by the early tramway services; indeed, the number 19 tram served Glasnevin until the replacement of the service by buses in 1939. With the formation of the Dublin United Transport Company in the late nineteenth century, the people of Dublin enjoyed a public transport system for the first time.

Glasnevin has come a long way since the age of St. Mobhí. The area has since transformed into a modern suburb, on the outskirts of the city centre.