(According to my definition of a sport)
Absolutely not.
A sport requires participation by athletes, Poker players are not athletes.
A sport requires physical talent. Sitting in a circle for long periods of time does not qualify as physical talent.
Poker is
gambling.
I hate when people try to call everything under the sun a sport. Activities do not have to be sports to make them cool. Golf is not a sport but its very cool. Darts is not a sport. Billiards is not a sport. Poker is not a sport. They are all fun activities that require skill, but do not require athleticism. Thats why they are not sports.
This is the example I always use. If the world was having an international athletic competition, and they did not tell anyone what games the people would be competing in, would you send a poker player or a football player to represent your country? A golfer of a basketball player? Sports are played by athletes. Poker players and golfers are in no way athletes.
It doesn't take anything away from poker to not be called a sport. Lets just leave at a card game. There is nothing athletic about playing cards.