Hugo Krabbe (3 February 1857 – 4 February 1936) was a Dutch legal philosopher and writer on public international law. Known for his contributions to the theory of sovereignty and the state, he is regarded as a precursor of Hans Kelsen. Like Kelsen, Krabbe identified state and law, and argued that state law and international law were parts of a single normative system; contrary to Kelsen, he conceived of the identity between state and law as the outcome of an evolutionary process.