The categorization of South Korea as a middle power has become normalized. A flood of academic papers, think-tank reports, workshops and seminars support the claim. Yet, despite widespread agreement that South Korea is a middle power, and a plethora of research supporting the claim, South Korea has never demonstrated characteristic middle power diplomatic behavior in addressing its most significant challenge - North Korea. This paper addresses the question of middle power diplomacy and North Korea. It first distinguishes the academic, political, and policy rationale in the use of the middle power concept before tracing its use in the context of North Korea. From middle power literature, the study extracts factors necessary for middle powers to secure diplomatic objectives before presenting an exemplary middle power diplomatic initiative. To conclude, the study explores potential reasons why South Korea has not demonstrated characteristic middle power diplomatic behavior in addressing North Korea.