Australia's most famous race has become one of the world's most popular with the Melbourne Cup trending in three countries on social media.

Won by German horse Protectionist and ridden by English jockey Ryan Moore, Australia's most famous race also reached a worldwide audience on twitter.

The race trended in Australia, New Zealand and the UK which was represented by seven runners.

It also trended in 11 cities including Sydney and its hometown of Melbourne, along with the less-obvious English towns of Stoke-on-Trent and Hull.

Twitter experienced a 66 per cent increase in tweets when the race jumped compared to 12 months ago with tweets-per-minute peaking at 3.09pm (AEDT) just after Protectionist crossed the line first.

Horses who received the most mentions were the winner and runner-up Red Cadeaux, along with ill-fated favourite Admire Rakti.