<p>This book constitutes revised selected papers from the&nbsp;11th International Workshop on Engineering Multi-Agent Systems, EMAS 2023, which was held in London, UK, during May 29-30, 2023.</p><p>The 11 full papers and 7 short papers included in this volume were carefully reviewed and selected from a total of 25 submissions. They were organized in topical sections as follows:&nbsp;agent-oriented software engineering; agents and microservices; strategy, reasoning, and planning;&nbsp;engineering domains and applications;&nbsp;agents in hypermedia environments; frameworks, tooling, and devops.</p>