Speciation is responsible for creating the world’s biological diversity. Attempts to understand and explain speciation date back to Darwin’s seminal work ‘On the origin of species’ (1859). Yet, even today, more than 150 years later, fundamental scientific questions about how genetic, geographical, ecological, evolutionary, and environmental factors interact to create species remain wide open. These questions are now being addressed, with recently increasing vigor, at the forefront of biological research. While classical theories of speciation emphasize geographical isolation and often relegate ecological factors to the background, modern theories tend to highlight, in addition, the important roles of ecological interactions and sexual selection. Many other issues, concerning the roles of spatial structure, hybridization, genetic drift, pleiotropy-based constraints, mate choice, and environmental change are also still unresolved. Fueled by new developments in genomic studies, comparative approaches, and mathematical modeling, the last decade has brought an unprecedented surge in speciation research. Topical challenges for the future include the integration of genomics with ecological speciation research, and the integration of speciation research with ecosystem science. Against this backdrop of burgeoning research activities and intensified scientific discussions, the new Gordon Research Conference (GRC) on ‘Speciation’ will serve as an inroad into the field of speciation research for a new generation of young researchers and at the same time enable senior scientists to develop connections outside their immediate area of expertise. A major focus of the conference will be to facilitate bridge-building among disparate approaches to speciation research and between the European, North American, and Asian communities of speciation researchers. We will therefore promote lectures surveying fields of contemporary speciation research and encourage geographically balanced contributions and discussion sessions of an integrative nature. The Gordon Research Conference on ‘Speciation’ will build on, and greatly enhance, the impacts and international outreach of recently intensified scientific networking in speciation researchers across Europe, which included the organization of two major international speciation conferences and proved very successful for establishing collaborations and catalyzing discussions across disciplinary divides in speciation research.