Relatively recent developments in metalloenzyme and organometallic chemistry have targeted a growing link between these outwardly incongruous fields, giving birth to a merger now popularly termed “bio-organometallic” chemistry. The astonishing discovery of CO and CN ligands bound to dinuclear iron sites in billion-year-old hydrogenase enzymes has led to a new paradigm and triggered an explosion of research on bioinspired chemistry. The article will focus on the impressive array of organometallic chemistry principles that work in concert in the structure and function of H₂ases. Molecular H₂ is at the forefront of bioinspired energy, and its production and storage are critical for renewable energy systems. Biomimetic inorganic chemistry and photochemistry involving water splitting for H₂ production has erupted in the past decade and will also be reflected upon here.