Year two teacher Kate Rhodes said every class in the school had adopted a nation, except New Zealand or Australia, and learned about the country in the classroom before heading outside and representing the country on the field.
She said the competition had been separated into levels where juniors played juniors and seniors played seniors - and everyone had been looking forward to it.
"We've got about 500 kids here, and this way the competition means everyone can get involved," she said.
"The senior kids can be quite competitive so this way they can have a good run around and the juniors can take part too without it being too rough," Mrs Rhodes said.
"We've tried to encourage everyone to play."
The youngsters had been studying their adoptive countries for the past few weeks before yesterday's festival day.
Mrs Rhodes said it had been exciting watching the pupils learn about different nations.
Tauranga Boys' College students helped referee the games.