Logic programming is one such example. Prolog and its syntactic subset Datalog are taught as part of countless CS degrees throughout the entire world.
In fact, logic in general is such an example. At least a basic treatment of propositional logic and predicate logic, computation, unification, resolution and sequent calculus is a common ingredient of CS degrees all around the world.
Other common examples include probability theory, statistical tests and complexity theory, all of which are part of many CS degrees, both at the undergraduate and graduate level.
In all these examples, organizations that need these skills tend to hire people that already have them at least to some degree, making it unlikely to encounter these topics at work for the first time.