The only two official languages of the Olympics are French and English. Announcements are made in both languages and the language of the host country, but because the Olympics are being held in the UK this year, official announcements will only be made in French and English. But with over 14,000 participants from 205 different countries, you can bet that there will be a lot of languages heard at the games this year.
The French language is an official language of the Olympic Games because other than being an influential language worldwide and an official language in 29 countries, it was a Frenchman, Baron Pierre de Coubertin, who brought the games back to modern history 1,000 years after it's last event in Olympia, Greece. The first modern Olympic games were held in Athens Greece and the first winter Olympics were held in Chamonix, France. Also, the headquarters of the International Olympic Committee are in Lausanne, Switzerland, a French-speaking city in the French-speaking part of Switzerland. Announcements are generally made first in French and in English second. When the Olympics are hosted in a country where neither of these languages is spoken, announcements in the host language will be given last.