The N11 road is a national primary road in Ireland, running for 129 km (80 mi) along the east side of Ireland from Dublin to Wexford. It passes close to Bray, Greystones, Newtownmountkennedy, Ashford, Wicklow, Arklow, Gorey, and Enniscorthy. Beyond Wexford, the route continues to Rosslare as the N25. The road forms part of European route E01. As of July 2019 the N11/M11 is of dual carriageway or motorway standard from Dublin as far as Oilgate in County Wexford.

The road is a busy commuter route, being the only dual carriageway passing through the south eastern suburbs of Dublin, as well as close to the many commuter towns along the east coast as far south as Gorey. Summer Friday and Sunday evenings also see very heavy traffic as Dubliners decamp to and return from their many holiday home locations along the County Wicklow and County Wexford coastlines.

The N11 commenced where it met the N4 on the south end of O'Connell Bridge in Dublin city centre. The route proceeded along D'Olier Street, College Street (and in the opposite direction, Westmoreland Street). The route continued around College Green and Grafton Street (and in the other direction, Suffolk Street, Church Lane and Dame Street). From here, the route continued out of the city via Nassau Street, Kildare Street, North side of St. Stephen's Green, Merrion Row, Baggot Street Lower, Pembroke Street Lower, Fitzwilliam Square West and Pembroke Street Upper. This route section in the other direction (into the city centre) ran via Leeson Street Lower, East and North sides of St. Stephen's Green and Dawson Street. The N11 ran in both directions along Leeson Street Lower after the junction with Pembroke Street. Having crossed the Grand Canal the route divided again for a portion of Leeson Street Upper, with outbound traffic proceeding via Sussex Road. The route continued via Morehampton Road and Donnybrook Road, through Donnybrook. Eventually converting from single carriageway (including bus lanes either side) to dual carriageway at Donnybrook Church, which marks the beginning of what is known as the Stillorgan Road.

The Stillorgan Road brought the road past Belfield, where University College Dublin is located (and accessed from a grade-separated interchange on the dual carriageway - the first full interchange built in Ireland) and onwards to its junction with Mount Merrion Avenue.

This former section of the N11 is now the R138.

Heading south, the N11 currently starts in Mount Merrion at the junction with the N31 to Dún Laoghaire harbour.

From this junction it heads south to Stillorgan village. Stillorgan village is bypassed to the east by the N11 dual carriageway, which proceeds southeast through Galloping Green, bypassing Leopardstown and Foxrock to the east also. Then the Cabinteely Bypass and part of the Bray Road bring the N11 via Loughlinstown to north of Shankill, where the M11 motorway commences as the Bray/Shankill Bypass.

The entire length of the N11, from Mount Merrion to the Loughlinstown roundabout, is provided with a Quality Bus Corridor (QBC) bus lane. Dublin Bus Route 46A operates over this stretch of road as far as the junction with Kill Lane in Foxrock. The E1 links Bray to various parts of the city centre as far as Northwood near Ballymun