Open Data Day (ODD) is an annual celebration of open data all over the world. Groups from likely every country create local events on the day where they will use open data in their communities. ODD is maintained and supported by the Open Knowledge Foundation (OKFN) through the Open Knowledge Network. As a way to increase the representation of different cultures, since 2023 the opportunity for organisations is offered to host an Open Data Day event on the best date within a one-week period, this year from 1 to 7 March, 2025. 

This year's thematic focus is 'Open Data to Tackle the Polycrisis'. Each year, the theme is deliberately broad to accommodate the most diverse practices and perspectives of working with open data for the public interest. In 2025, the organisation wants to address some of the most pressing issues of our time and go beyond climate justice. That's why the theme is developed around the concept of polycrisis, and more specifically the intersections between poverty and multiple inequalities, violence and conflict, and climate and disaster response.