The first generation fusion reactors and the fusion experiments leading up to them will burn deuterium-tritium fuel. The presence of tritium will require monitoring for reasons of health and safety, and for process control. This paper presents the tritium monitoring requirements of fusion and gives a summary of the status of research. These requirements are similar to those of Ontario Hydro which, because of tritium in the moderator and heat transport water of their CANDU heavy water nuclear reactors, has gained much practical experience in the monitoring of tritium for health and safety reasons. This experience and Ontario Hydro's future tritium monitoring plans are discussed, followed by some tritium monitoring R&D suggestions.