This book constitutes the proceedings of the 1st Workshop on EI-MiGA@IJCAI 2026 for Human Behavior Analysis and Interaction for Emotional Intelligence, in conjunction with IJCAI 2026, held in Bremen, Germany, during August 15-21, 2026.The 13 full papers presented in this volume were carefully reviewed and selected from 20 submissions. They are grouped into the following topics: Micro-Gesture Challenge and Recognition; Explainability in Emotional Intelligence; Affective Interaction and Social Computing.