Activity centre is a term used in urban planning and design for a mixed-use urban area where there is a concentration of commercial and other land uses. For example, the central business districts of cities (CBD) are also known as “Central Activities Districts” (CAD) (also known as Downtown in North America or "Central Activities Zone" in the United Kingdom) in recognition of the fact that commercial functions are not the only things that do or should occur there. The term activity centre can also be used to designate an area for mixed-use development, whatever its current land use happens to be.
Activity centres can vary greatly in size from the central districts of large cities to regional commercial areas to neighbourhood shopping centres and strips. They can also refer to specialised agglomerations of activities such as urban university campuses or research institutes. They are an important concept in urban planning for Transit-oriented development or TOD, which seeks to intensify landuses around public transport nodes to facilitate greater sustainability in the way people and goods move around cities.
Activity centres are a key component of contemporary strategic planning for large dispersed cities like those in Australia, Canada, the USA and New Zealand. Examples of such planning include the Melbourne 2030 strategy for Melbourne and the City of Cities metropolitan strategy for Sydney.