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 we offer the opportunity for organisations to host an Open Data Day event on the best date within a one-week period.