This synthesis identifies future research needs in atmospheric mercury science, based on a series of review papers, as well as recent developments in field data collection, modeling analysis, and emission assessments of speciated atmospheric mercury. Research activities are proposed that focus on areas that we consider important. These include refinement of mercury emission estimations, quantification of dry deposition and air–surface exchange, improvement of the treatment of chemical mechanisms in chemical transport models, increase in the accuracy of oxidized mercury measurements, better interpretation of atmospheric mercury chemistry data, and harmonization of network operation. Knowledge gained in these research areas will significantly improve our understanding of atmospheric cycling from local to global scales.