The Flag of County Durham is the flag of the historic county of Durham. It was registered with the Flag Institute as the flag of the county in 2013, after winning an online competition to decide a flag for the county.
A competition to design a new flag for County Durham was launched in July 2013 on the blog of Andy Strangeway, who had already established flags for the Ridings of Yorkshire. The competition noted that County Durham was the only traditional county in the North of England without a flag, after the adoption of the flags of Cumberland and Westmorland in 2011 and 2012.
The winning flag was chosen from six finalists, and was designed by twins Katie and Holly Moffatt and their father James Moffatt from Chilton, County Durham. The flag features the Cross of St Cuthbert, counterchanged on the county colours of blue and gold.