This volume LNCS 13912 constitutes the refereed proceedings of the 20th International Symposium on Web and Wireless Geographical Information Systems, W2GIS 2023, in June 12-13, 2023 in Quebec City, QC, Canada. The 9 full papers presented together with 2 short papers were carefully reviewed and selected from 14 submissions.

Keynote.- An approach for geosensor network optimization to support decisions at multiple Scale.- Sensors Networks and Data Steaming.- Towards Integration of Spatial Context in Building Energy Demand Assessment Supported by CityGML Energy Extension.- Three-stage Framework to Estimate Pedestrian Path by Using Signaling Data and Surveillance Video.- Mobility and Navigation.- Investigating the Navigational Behavior of Wheelchair Users in Urban Environments Using Eye Movement Data.- New Approach for Accessibility Assessment of Side-Walks for Wheelchair Users Considering the Sidewalk Traffic.- AI for Mobility Data Analytics.- Mobility Data Analytics with KNOT: the KNime mObility Toolkit.- Bus Journey Time Prediction with Machine Learning: An Empirical Experience in Two Cities.- A Novel GIS-Based Machine Learning Approach for the Classification of Multi-Motorized Transportation Modes.- Volunteered Geographic information (VGI).- Cimemountainbot: A Telegram Bot to Collect Mountain Images and to Communicate Information With Mountain Guides.- A New Feature Matching Method for Matching OpenStreetMap Buildings with Those of Reference Dataset.- Network Analysis and Geovisualization.- Geovisualisation generation from semantic models: a state of the art.- A Heterogeneous Information Attentive Network for the Identification of Tourist Attraction Competitors.- Poly-GAN: Regularizing Polygons with Generative Adversarial Networks.