Ernst Karl Falkbeer (June 27, 1819 - December 14, 1885) was a German-speaking chess master and journalist from Austria-Hungary.
Born in Brünn, a town that in 1819 belonged to the Habsburgian Austria, and which today is known as Brno in the Czech Republic, Falkbeer moved to Vienna to study law, but ended up becoming a journalist. During the European Revolutions of 1848, he fled Vienna for Germany. He played chess with German masters Adolf Anderssen and Jean Dufresne in Leipzig, Berlin, Dresden, and Bremen.
In 1853 Falkbeer was allowed to return to Vienna. Two years later, in January 1855, he started the first Austrian chess magazine, Wiener Schachzeitung, which lasted only a few months. He went to London where he played two matches against Henry Bird. Falkbeer lost the 1856 match (+1 −2), but won the 1856/7 match (+5 −4 =4). At the Birmingham 1858 knockout tournament he beat Saint-Amant in round two (+2 −1), but lost in the round four final to Johann Löwenthal (+1 −3 =4) to finish second.
Falkbeer edited a chess column for The Sunday Times from April 1857 to November 1859. He returned to Vienna in 1864, later writing a chess column in Neue Illustrierte Zeitung from 1877 to 1885. He died in Vienna on December 14, 1885.
Falkbeer is more famous for his contributions to chess theory than for his individual play. He introduced the Falkbeer Countergambit, still considered one of the main lines in the King's Gambit Declined. Siegbert Tarrasch held the view that Falkbeer's Countergambit refuted the King's Gambit entirely. In fact King's Gambit was a common chess opening until Falkbeer's counter-gambit became commonly known in the chess world. If accepted, quite a few interesting variants of King's Gambit, for instance the Muzio Gambit, may appear. But after the invention of Falkbeer all variants of King's Gambit has been reduced to only seldom being played and only at lower levels. No other "new" opening move - in any kind of chess-opening theory has had such a profound influence on the game of chess after the invention of Falkbeer's Counter Gambit.