Around 2000 people
On the XXIX Olympiad in Bejing, there are 204 countries and territories competing. Of the 192 UN recognized countries, the only country not to have entered is Brunei, having failed to submit any athletes. All other countries have entered.
Assuming modern Olympic games (not ancient Greece)
There is still some discrepencies in how many countries competed as national teams werent recognised like they are now, however the 14 most likely teams are
14 nations participated in the first olympic games held in 1896.
MICH JORDAN competed & won in the Olympic Games
Japan,Jamaica and Jordan
Qatar has competed in the Olympic games 8 times. The first year they competed in the Olympic Games was 1984, and they have participated in every one since then.
2012 was her first year on the olympic gymnastics team in which she competed in 4 events
Greece and United Kingdom
Women competed at the Olympic Games for the first time at the 1900 Paris Olympics.
The Greek people and Athenians and Spartans competed in the Olympic games of Greek.
Switzerland, Great Britain and Greece
Australia, France, Great Britain, Greece and Switzerland have competed in all of the Olympic games as of 2012.