From spatial to spatio-temporal and, then, to mobility data. So, what's next? it is the rise of mobility-aware integrated Big Data analytics. The Big Mobility Data Analytics (BMDA) workshop, initiated in 2018 with EDBT Conference, aims at bringing together experts in the field from academia, industry and research labs to discuss the lessons they have learned over the years, to demonstrate what they have achieved so far, and to plan for the future of "mobility".In its 4th edition, BMDA workshop will foster the exchange of new ideas on multidisciplinary real-world problems, discuss proposals about innovative solutions, and identify emerging opportunities for further research in the area of big mobility data analytics, such as deep learning on mobility data, edge computing, visual analytics, etc.. The workshop intends to bridge the gap between researchers and big mobility data stakeholders, including experts from critical domains, such as urban / maritime / aviation transportation, human complex networks, etc.BMDA is partially supported by the EU Horizon 2020 projects and organizations: VesselAI (Enabling Maritime Digitalization by Extreme-scale Analytics, AI and Digital Twins), MASTER (Multiple Aspects Trajectory Management and Analysis).