The geological and paleontological potential of the James Ross Basin, located at the northeastern tip of the Antarctic Peninsula, seems inexhaustible. A late Mesozoic–early Cenozoic sedimentary succession nearly 7 km thick is exposed within the basin, and numerous fossiliferous levels make it possible to carry out fundamental research into the evolution of both marine and continental floras and faunas at this high paleolatitude locality. This situation, linked to the spirit of scientific collaboration that governs Antarctica thanks to the Antarctic Treaty System, has resulted in innumerable important scientific contributions to date. In this Special Issue, “Geology and Paleontology of the James Ross Basin, Antarctic Peninsula”, the essence of the Antarctic Treaty is honored and celebrated. Ten original scientific works are presented by researchers from ten different countries (Argentina, Australia, Belgium, Canada, Chile, New Zealand, Poland, Spain, UK, USA) in a collaboration that highlights the current state of knowledge of this classic geological site, addressing both highly relevant questions and opening exciting new lines of inquiry for Antarctic Earth Sciences. The contributions presented here have been divided into the following categories: eight Reviews, one Article, and one Trend.