This book constitutes the proceedings of the 8th International Workshop on Accelerator Programming Using Directives, WACCPD 2021, which took place in November 2021. The conference was held as hybrid event.  WACCPD is one of the major forums for bringing together users, developers, and the software and tools community to share knowledge and experiences when programming emerging complex parallel computing systems. The 7 papers presented in this volume were carefully reviewed and selected from 11 submissions. They were organized in topical sections named: Directive Alternatives; Directive Extensions; and Directive Case Studies.