What is the “proper” way to cast Hibernate Query.list() to List?

Short answer @SuppressWarnings is the right way to go.

Long answer, Hibernate returns a raw List from the Query.list method, see here. This is not a bug with Hibernate or something the can be solved, the type returned by the query is not known at compile time.

Therefore when you write

final List<MyObject> list = query.list();

You are doing an unsafe cast from List to List<MyObject> – this cannot be avoided.

There is no way you can safely carry out the cast as the List could contain anything.

The only way to make the error go away is the even more ugly

final List<MyObject> list = new LinkedList<>();
for(final Object o : query.list()) {
    list.add((MyObject)o);
}