Therefore, there isn't a single person credited with "discovering" goldfish. Instead, it was a gradual process of selective breeding over generations that led to the beautiful, golden fish we know today.
Who discovered goldfish?
Goldfish weren't "discovered" in the sense of being found in the wild for the first time. They were actually selectively bred from a common carp species, the Prussian carp (Carassius gibelio), in China over a thousand years ago.