A High-quality dual carriageway (HQDC) is a road category in Ireland. It is defined as an all-purpose dual carriageway road type built to near motorway standards, but without motorway classification or motorway restrictions. High-quality dual carriageways have full grade-separated access and do not have junctions with minor roads. Such roads in the Republic of Ireland have been built as part of the 2000–2006 and 2007–2013 National Development Plans, including interurban routes from Dublin to other cities.
While HQDCs or roads of similar type exist in a number of countries this article concentrates mainly on such roads in Ireland.