This book constitutes the revised selected papers of the 6th Ibero-American Congress on Smart Cities, ICSC-Cities 2023, held in Mexico City and Cuernavaca, Mexico, during November 13-17, 2023. The 19 full papers included in this book were carefully reviewed and selected from 94 submissions. They were organized in topical sections as follows: Urban Informatics for Smart Cities; Optimization, Smart Industry, and Smart Public Services; Internet of Things; Computational Intelligence and Urban Informatics for Smart Cities and Innovative Informatic Approaches for Smart Cities.