Transition metal complexes are widely applied in the physical and biological sciences. They play pivotal roles in aspects of catalysis, synthesis,materials science, photophysics and bioinorganic chemistry.Our understanding of transition metal complexes originates from Alfred Werner’s realisation that their three-dimensional shape influences their properties and reactivity.1The intrinsic link between shape and electronic structure is now firmly underpinned by molecular orbital theory.2-5Despite over a century of advances in this field, transition metal complexes remain limited to a handful of well understood geometries. Archetypal geometriesfor six-coordinate transition metals are octahedral andtrigonal prismatic. Although deviations from idealbond angles and lengths are common,6alternativeparent geometries are staggeringly rare.7Hexagonal planar transition metalsare restricted to those found in condensed metallic phases,8the hexagonal pores of coordination polymers,9orclusters containing more than one transition metal in close proximity.10,11Although [Ni(PtBu)6] could beassignedas a hexagonal planar complex,12,13a molecular orbital analysis ultimately led to the conclusion that it is best described as a 16-electron complex with a trigonal planar geometry.14Here we report the isolation and structural characterisation of the first simple coordination complex in which six ligands form bonds with a central transition metal in a hexagonal planar arrangement.The discovery has the potential to open up new design principles and new ways of thinking about transition metal complexes which could impact multiple fields of science.