It is not. The only languages (that people have actually heard of, at least) that are OO are Smalltalk, Ruby, and Objective-C. Swift also includes OO features, enabled with the @objc directive, for the sake of backwards compatibility with Objective-C, but "Swift proper" has tried to distance itself from the concept.

Go channels share some basic conceptual ideas with message passing, but they don't go far enough to bear any direct resemblance to OO; most notably they are not tied to objects in any way.