Patron saints are chosen as special protectors or guardians over all areas of life.
Traditionally people see them as symbols of how to live a better life.
You can have patron saints of all sorts of things, like jobs, organisations and animals.
For example St Francis of Assisi loved nature and wildlife so he was made the patron saint of animals.
But nations can have patron saints too.
England, Ireland, Scotland and Wales each has their own national day named after their patron saint.