Responsibilities for traditional coast guard duties in Australia are distributed across various federal, state and community agencies. The de facto coast guard of Australia is the Maritime Border Command, a joint command of the Australian Defence Force and the Australian Border Force which works alongside the Australian Federal Police, the Australian Fisheries Management Authority, and the Australian Maritime Safety Authority. Each state and territory government have specific maritime safety agencies and police marine units. In addition, there are several private volunteer coast guard organisations which act as auxiliary search and rescue services and maritime safety educators with the largest organisations being the Royal Volunteer Coastal Patrol established in 1937, the Australian Volunteer Coast Guard established in 1961, and Marine Rescue New South Wales established in 2009.

The Maritime Border Command is the de facto coast guard of Australia. The Maritime Border Command is a joint unit of the Australian Defence Force (the Royal Australian Navy Patrol Force and the Royal Australian Air Force Surveillance and Response Group) and the Australian Border Force (Marine Unit and Coastwatch aircraft). It is responsible for border protection in the exclusive economic zone of Australia and its 19,650 kilometres of coastline and issues such as illegal fishing and exploitation of natural resources, maritime terrorism and piracy, biosecurity threats, and marine pollution. The Australian Federal Police supports the Maritime Border Command and particularly the Australian Border Force with criminal investigations, law enforcement and national security matters. From August to December 2021, the Maritime Border Command participated in the Royal Australian Navy and OCIUS Bluebottle trial of unmanned surface vehicle (USV). The purpose of the trial was to assess the use of the Bluebottle as a maritime surveillance system to support maritime security. They tested its ability to detect small boats that pose a threat within its area of operation.

The Australian Maritime Safety Authority is responsible for maritime safety and seaworthiness of Australian and foreign vessels in Australian waters including compulsory pilotage, aids to navigation, the Australian Rescue Coordination Centre and coordination of search and rescue operations, and management of Australia's international maritime obligations.

The Australian Fisheries Management Authority is responsible for the management and sustainable use of fisheries resources and for combating illegal fishing activities in the Australian Fishing Zone. There are three main branches: Fisheries Operations, Fisheries Management, and Corporate Services. Fisheries Operations is primarily responsible for combating illegal activities, data management, and international communication. Fisheries Management is responsible for economics and policy.

The Office of Transport Security has various responsibilities for maritime security.

Each State Government also has agencies with coast guard responsibilities.

Marine Rescue Queensland, a branch of the Queensland Police Service, is responsible for maritime safety and rescue.

Neither the Royal Volunteer Coastal Patrol nor the Australian Volunteer Coastguard are active in Western Australia, which is the largest state with the longest coastline. Inshore close to towns the West Australian Police co-ordinate local search and rescue between various state agencies (such as DOT, Fisheries and Water Police). Marine Rescue WA Groups form the core of the system with three main areas of emergency response / search and rescue (SAR), education, and radio monitoring. MR WA groups (37) are part of DFES (Department of Fire and Emergency Services) The 3 largest MR groups are part of DFES including Mandurah the oldest VMR group in WA.