Will goldfish eat snails?

My snails lived happily with my goldfish. Then I fed my fish a garden slug, and they later attacked the snails. Later again, I did something that (in hindsight) was even more stupid! I fed the snails some earthworms and a garden snail. They ate these up and then killed a small aquatic snail that they had previously happily lived with. And now they seem to be attacking my large Mystery Snail, too. Grump! :(

Yes they will, I bought two Golden Apple snails once, they were gone within a day!
Goldfish are snail eaters par excellance!!
They have a way of sucking the snail out of its shell, then grinding it up with their Pharyngeal (hope I spelt that right!) teeth, which are located in the back of the mouth/throat area, rather than their jaws.
They will also eat anything that will fit into their mouths, even smaller Goldfish!

Goldfish will sometimes go after the antennae of the snails and larger fish will sometimes eat smaller snails. So, go with large snails and small fish if possible. Both species do well at about the same temp (65-75 deg. F) so they can be good tank mates. Both species are messy, though, so keep the numbers down and do partial water-changes regularly. And if you don't want the snails to breed, stick to one.

I have heard that goldfish will eat snails but I've never seen mine eat them. They tend to eat whatever will fit in their mouth so it wouldn't surprise me! If you are looking for a fish that will eat snails, try a clown loach. :)

No, definately not.