Illkirch-Graffenstaden (French pronunciation: ​[ilkiʁʃ gʁafənʃtadən]) is a commune in the Bas-Rhin department in Grand Est in north-eastern France. It is the second-largest suburb of the city of Strasbourg, and is adjacent to it on the south-southwest. Illkirch-Graffenstaden is one of the fastest-growing cities in France and probably in Europe, its population having more than doubled in fifty years (from 11,648 in 1968 to 26,780 in 2017).