As the name denotes, Sister Cities Australia Inc. (SCA) is an association of cities, towns, shires, ports and even states that have a Sister City relationship. SCA also takes a role in matching cities and towns in Australia with cities and towns both from overseas and within Australia seeking a sister city relationship. SCA is also the link between an Australian sister city or town and the many projects and ideas that have been experienced here and abroad.

Many cities, municipalities and shires in Australia have at least one sister city relationship with a city or town overseas, or within Australia with many have multiple affiliations.

The objective of Sister Cities Australia is to provide an umbrella of support and to promote these affiliations. SCA also aims to provide a forum for cultural, economic and educational interchange between communities and to encourage friendship, co-operation and understanding to improve peaceful co-existence worldwide.