What horse event has the most prize money?

The horse event with the most prize money is the Dubai World Cup. It is a Group 1 Thoroughbred horse race held annually at Meydan Racecourse in Dubai, United Arab Emirates.

The total prize money for the Dubai World Cup in 2023 was a whopping $12 million. This makes it the richest horse race in the world, attracting some of the best horses and jockeys from around the globe.

It's worth noting that while other horse events like the Kentucky Derby or the Prix de l'Arc de Triomphe have a significant amount of prize money, they are not as high as the Dubai World Cup.