Tactical urbanism is an approach to the planning and intervention of urban space characterized by low cost, small scale, speed of execution, reversibility and citizen participation in decision-making. The objective is to transform the city to make it more pleasant, welcoming, sustainable and safe by questioning the use and occupation of public spaces.[2]​.

Tactical urbanism usually uses ephemeral and portable urban elements, such as paint or street furniture, to mark the new use of that space without altering the infrastructure. This allows us to experimentally evaluate whether the intervention has the desired effect, whether improvements can be included or whether the change in use should be made permanent.[2]​.

The term tactical urbanism became popular in the second half of the 2000s to refer to a multitude of citizen actions and urban activism that began to emerge around the world and whose common objective was to reconquer spaces for citizens and so that the neighbors themselves could participate in the modeling of their daily environment.[3][4]​.

Tactical urbanism is influenced, among others, by the contributions of urban planners, architects, human geographers, sociologists or philosophers such as Jane Jacobs, Peter Hall "Peter Hall (urban planner"), Hannah Arendt, Jürgen Habermas, Paul Davidoff") or David Harvey.[5]​.

Depending on the ideological perspective, the duration of the intervention or whether these actions are carried out by institutions or activists, the concept is also called emergent urbanism, guerrilla urbanism, punk urbanism, participatory urbanism, precarious urbanism, bottom-up urbanism, urban prototyping or planning by doing.[5]​.