Semiconductor photocatalysis has important applications such as achieving sustainable energy generation and treating environmental pollution. TiO2 has been the most widely-researched photocatalyst, but suffers from low efficiency and narrow light response range. Combining TiO2 with carbonaceous nanomaterials is being increasingly investigated as a means to increase photocatalytic activity, and demonstrations of enhancement are plentiful. This review surveys the literature and highlights recent progress in the development of nanocarbon-TiO2 photocatalysts, covering activated carbon, carbon doping, carbon nanotubes, -fullerenes, graphene, thin layer carbon coating, nanometric carbon black and more recently developed morphologies. Mechanisms of enhancement, synthesis routes and future applications are summarised and discussed. New insight and enhanced photocatalytic activity may be provided by novel nanocarbon-TiO2 systems. Ongoing challenges and possible new directions are outlined.