OpenGeofiction (abbreviated OGF) is an online collaborative mapping project focused on fantasy cartography and worldbuilding of a world analogous to Earth.

[2][3] OpenGeofiction was founded in September 2013 by the German software developer Thilo Stapff and urban planner Johannes Bouchain.

[4][5] OpenGeofiction portrays a verisimilar world based on modern technology but fictitious geography and culture.

[9] Places can be mapped in OpenGeofiction to illustrate stories or establish scenes for role-playing games.

[6] In 2018, OpenGeofiction data was used to model urban population movements in a hypothetical emergency evacuation using argument technology.