Is the Dubai airport the busiest in the world?

No. The operator of Heathrow, BAA, claims that Heathrow is the "world's busiest international airport", but Heathrow is only the world's third-busiest airport by total passenger traffic, after Atlanta-Hartsfield-Jackson and Chicago O'Hare, which are also international airports. However, Heathrow has the highest number of passengers bound for international destinations.