Place Eugène Flagey (in French: Place Eugène Flagey, in Dutch: Flageyplein, usually shortened to Flagey by locals), is a square in the Brussels municipality of Elsene (Ixelles), Belgium. It was named in honour of Eugène Flagey, mayor of Elsene/Ixelles from 1935 to 1953. With ten streets converging at Flagey Square, it is one of the best connected crossroads in the city, directly adjacent to the neighbouring Elsene/Ixelles Ponds (the street separating them now will disappear). A large flood control reservoir (necessary due to the low-lying terrain and high groundwater level) and a parking lot have been built under the square. The area comprising the square was covered by the Elsene/Ixelles Ponds until 1860 when one of the original ponds was drained as part of new urban design.