Updated: Jul 26, 2021
The United States has, by far, the most horses in the world , apart from it being a large country the U.S has more than 10 Million wild and recreational Horses. But obviously records are growing and changing everyday and like wise other big counties like China are the next to follow. And although European countries have large numbers they don't have large quantities of wild horses.
So yes the main answer to this question is the United States has the most Horses in the world. And like Humans the population will continue to grow.
The most popular Breed in the U.S is The Quarter horse with over two million registered horses living in America and over 400,000 international registered horses. With over two million Quarter horses registered worldwide, it is no wonder that these sturdy equines have become one of the most popular breeds to own.