Top 10 Largest Air Force in the World. This list of the Top 10 Largest Air Force in the World is by no means accurate. Numbers are gathered from different sources. The country's military aircraft secrecy is also a big factor. The top 3 biggest air force in the world: United States of America (USA) is the largest air force in the world, followed by Russia, as the second largest air force in the world; then China being the third largest air forces in the world.