It begins at the southern side of the Grand Canal and stretches along the Rathmines Road as far as Rathgar to the south, Ranelagh to the east, and Harold's Cross to the west.

Rathmines is a commercial and social hub and was well known across Ireland as "Flatland"—an area where subdivided large Georgian and Victorian houses provided rented accommodation to newly arrived junior civil servants and third-level students from outside the city from the 1930s.

[5] Like many of the surrounding areas, it arose from a fortified structure which would have been the centre of civic and commercial activity from the Norman invasion of Ireland in the 12th century.

At this time, Rathmines and the surrounding hinterland were part of the ecclesiastical lands called Cuallu or Cuallan, later the vast Parish of Cullenswood, which gave its name to a nearby area.

Cuallu is mentioned in local surveys from 1326 as part of the manor of St. Sepulchre (the estate, or rather liberty, of the Archbishop of Dublin, whose seat as a Canon of St. Patrick's Cathedral takes its name from this).

In more recent times, Rathmines was a popular suburb of Dublin, attracting the wealthy and powerful seeking refuge from the poor living conditions of the city from the middle of the 19th century.

A substantial mansion, generally called Rathmines Old Castle, was built in the seventeenth century, probably at present-day Palmerston Park, and rebuilt in the eighteenth; no trace of it survives today.

Rathmines is arguably best known historically for a bloody battle that took place there in 1649, during the Cromwellian conquest of Ireland, leading to the death of perhaps up to 5,000 people.

The Battle of Rathmines took place on 2 August 1649 and led to the routing of Royalist forces in Ireland shortly after this time.

In 1872 a Dr. O'Leary, who held a high estimate of the water quality, reported that the "spa" was in "a most disgraceful state of repair", upon which the developer and alderman Frederick Stokes sent samples to the medical inspector, Dr. Cameron, for analysis.

Dr. Cameron, a great lover of authority, reported: "It was, in all probability, merely the drainings of some ancient disused sewer, not a chalybeate spring."

On 25 April 1916, during the Easter Rising, Captain John Bowen-Colthurst, an officer of the 3rd battalion Royal Irish Rifles, went on a raiding party in Rathmines holding Francis Sheehy-Skeffington as hostage.

[9] During the Irish Civil War on 20 December 1922 Séamus Dwyer, a pro-treaty Sinn Féin politician, was shot dead in his shop at 5 Rathmines Terrace.

The following year also the long-awaited (since the 1861 accident) improvements to Portobello Bridge were carried out, the Tramway Company paying one-third of the total cost of £300.

[25] Today Rathmines is served by the Luas light rail system: Ranelagh on the Green Line is the most convenient for access to the main street, while the Charlemont, Beechwood (which is near the former railway station) and Cowper stops are also within walking distance of the area.