Some phytoplankton species, specifically members of the dinoflagellates, possess the remarkable ability to produce bioluminescence. Many bioluminescent species are globally distributed and some form blooms, which may sometimes be harmful. The bioluminescence system of dinoflagellates is unique from a biochemical, cellular and evolutionary perspective. Regulatory aspects of bioluminescence in relation to cell physiology remain largely unknown, as does the ecological niche of light-producing organisms. Meanwhile, in the field, bioluminescence has been used to study ecological dynamics within the plankton and to monitor toxic blooms. Studies on dinoflagellate bioluminescence have shed like on fundamental processes like cellular mechanotransduction, circadian rhythms and evolution of gene structure. The molecular components of the reaction have been used as reporters in biomedical applications and whole cells have been used to visualize fluid flow. Herein, we introduce key concepts and discuss current research that involves bioluminescent dinoflagellates. The research being conducted spans several different fundamental and applied fields, highlighting the vast benefits that dinoflagellate bioluminescence studies offer to biology and engineering.