World Cities Day brings Urban October to an end on 31 October each year and was first celebrated in 2014. As with World Habitat Day, a global observance is held in a different city each year and the day focuses on a specific theme.

On 31 October 2026, the Global Observance of World Cities Day will be related to "Regenerating the City: Adequate Housing for All". The theme focus is on addressing urban regeneration as a catalyst for achieving adequate housing for all. It will showcase how combining area-based regeneration with housing and informal settlements strategies can deliver inclusive climate-resilient neighborhoods, consistent with the principles of adequate housing for all. It will also emphasize participatory, community-led regeneration, supported by safeguards that prevent displacement and ensure benefits for existing residents through improved housing.