This book constitutes the proceedings of the 4th OpenSHMEM Workshop, held in Annapolis, MD, USA, in August 2017.The 11 full papers presented in this book were carefully reviewed and selected from 14 submissions. The papers discuss a variety of ideas for extending the OpenSHMEM specification and making it efficient for current and next generation systems. This includes new research for communication contexts in OpenSHMEM, different optimizations for OpenSHMEM on shared memory machines, exploring the implementation of OpenSHMEM and its memory model on Intel’s KNL architecture, and implementing new applications and benchmarks with OpenSHMEM.