The Fourth International Conference on Fault and Top Seals will provide an opportunity to hear the latest in fault and top seal analysis for both research and industry applications. The objective is to highlight and discuss advances in research and technology since the last conference in Montpellier in 2012, of interest across the geoscience and engineering communities. It is anticipated that the conference will help to identify future research and development themes which will underpin major improvements in our understanding of fault and top seals within the areas of hydrocarbon exploration & production, hydrogeology, CO2 sequestration and nuclear waste disposal. The main objective of the conference is to improve the capability of predictive methods and flow models in the full range of application areas. The content of the meeting will be wide ranging, from pore- and outcrop-scale through to basin-scale, and incorporating geology, geophysics, geochemistry and engineering. Integrated case studies are particularly welcomed. Oral and poster presentations will be complemented by ample discussion sessions and a conference fieldtrip.