The variety of materials that fall in the diamond category is vast and increasing. From single, to micro to nano-crystalline, diamond can be highly electrically insulating or synthesized to possess varying degrees of conductivity. Diamond in all its forms is without peer in terms of chemical stability exhibits excellent biocompatibility and is famously mechanically robust. Diamond is however, a difficult material with which to fabricated devices owing to its extreme hardness, lack of ductility and weldability. New synthesis and fabrication methods in recent decades have overcome some of these drawbacks and diamond has enjoyed a surge in interest as a biomedical material. In the field of neural interfaces a grand goal is permanent, high fidelity connections with neural populations. Diamond's longevity, biocompatibility and biochemical inertness make it a highly promising material with which to achieve this goal. This review covers recent uses of diamond in the three critical areas of neural interfacing: diamond as a growth substrate, as a neurochemical sensor electrode material and as a direct neural recording and stimulation material. Looking towards the future, the enticing prospect of nano-diamonds as optically active neural interfaces is reviewed.