Flemming Ammentorp Østergaard (born 31 October 1943 in Det Gule Palæ (Danish: The Yellow Palace), Ordrup) is a retired businessman, best known as long-time chairman of Parken Sport & Entertainment, who owns the football club F.C.
He is also known as Don Ø due to his sometimes Southern European paternal appearance, a nickname he received in the 1990s, by the editors of the fanwebsite "Fusionsnipserne".
[1] Østergaard is primarily known from his leadership roles at Parken Sports & Entertainment A/S where he became Managing Director and later Chairman.
In March 2017 Flemming Østergaard received an 18 months jail sentence for deliberately manipulating the share price of Parken Sports & Entertainment A/S, events which took place during a period stretching 2007 and 2008.
In addition to the jail sentence, DKK 9 million was confiscated from Østergaard personally and Parken Sports & Entertainment A/S received a fine of DKK 13 million as a result of the share price manipulation.