In poker the term Triple Crown is used for winning a poker title on the three major poker tours: The World Series of Poker (WSOP), World Poker Tour (WPT) and up to 2016 the European Poker Tour (EPT). Since the EPT has been discontinued and rebranded as the PokerStars Championship, those wins are considered part of the crown.
Poker has the same term for a three time champion has horse racing does.