The GMC has temporarily registered 849 doctors from 141 countries to support their teams during the Olympics.
Overseas doctors are only permitted to treat their own athletes.
The GMC has rejected more than 40 applications, including one request from Mexico for the registration of a vet.
The French Olympic team has registered 58 doctors, the highest number from any country, to care for their 333 athletes - Britain's 542 competitors will be supported by 18 doctors.
Fiji, Micronesia, Saudi Arabia, Singapore, Nepal, Zambia, Honduras and Iraq have registered just one doctor each. Another 29 applications from around the world are being processed.
The GMC worked closely with the London Organising Committee of the Olympic and Paralympic Games (LOCOG) and the International Olympic Committee to ensure that the registration process was as simple as possible.
LOCOG paid the GMC approximately £24,000 to cover the cost of registering the team doctors of each country attending the games.
This is by far the largest number of doctors that the GMC have registered for a single event.
Dr Cindy Chang, chief medical officer for the US Olympic Team, which is bringing 46 doctors to the UK, said: ‘The entire GMC team was very thorough and helpful.’
‘Doctors play a vital role at all levels in all sports,’ said GMC chief executive Niall Dickson. ‘We are proud to have played our small part by enabling overseas doctors to come here and support their Olympic athletes during the Games.’