The Canadian Coast Guard Auxiliary (CCGA; French: Garde côtière auxiliaire canadienne, GCAC) is a Canada-wide volunteer marine association dedicated to marine search and rescue (SAR) and the promotion of boating safety, through association with the Canadian Coast Guard under the auspices of Canada's National Search and Rescue Program.

Members of the CCGA are usually recreational boaters and commercial fishermen who use their vessels to assist the Canadian Coast Guard with search and rescue (SAR) as well as boating safety education. CCGA members who assist in SAR operations have their vessel insurance covered by CCG, as well as any fuel and operating costs associated with a particular tasking.

The CCGA enables the CCG to provide maritime SAR coverage in many isolated areas of Canada's coastlines without having to maintain an active base and/or vessels in those areas. The auxiliary is dedicated to providing a permanent day and night search and rescue service to cover marine requirements in Canada and prevent the loss of life and injury.

Coastal lifesaving stations manned by volunteers pre-date Canadian Confederation (1867), with some coastal services in what is now Atlantic Canada dating to the early 1800s. The country's first motorized lifeboat was established in 1907 by volunteers at Bamfield, British Columbia.

Formal responsibility for organizing and overseeing search and rescue in Canada was given to the Minister of National Defence in 1951. This responsibility mostly fell to the Royal Canadian Air Force (RCAF) which, in coordination with the International Maritime Organization (IMO) and International Civil Aviation Organization (ICAO), delineated search and rescue regions (SRRs) to be overseen by rescue coordination centres (RCCs) that would manage SAR response activities.

Changes to the Canada Shipping Act in 1961 and the formation of the Canadian Coast Guard in 1962 saw the Department of Transport, which had responsibility for the CCG from 1962-1995, given responsibility for maritime search and rescue in support of the Minister of National Defence's mandate. As a result, the Minister of Transport designated "marine rescue controllers" who were CCG personnel that would work within the RCAF's rescue co-ordination centres. The RCCs were renamed joint rescue coordination centres (JRCCs) to denote the dual role of aeronautical and maritime search and rescue, as well as their joint operation by RCAF and CCG personnel.

CCG search and rescue officers (CGRO) first formally recognized volunteers in 1963. Volunteer "rescue agents" were individuals with access to seaworthy boats equipped with radios and volunteer "search masters” were individuals who served as local points of communication with CCG maritime rescue controllers operating in the RCCs and Maritime Rescue Sub-Centres. A metal sign depicting a ball and square day shape (distress) and the CCG-GCC crest was provided to identify search masters. A distinctive pennant based on the design of the CCG jack was also issued: white hoist, blue fly, single red maple leaf with the letters S and R on either side of the leaf, to identify rescue agent vessels.

By the mid 1970s, it became clear that a formal organization for training volunteer search and rescuers was necessary in order to improve the CCG's response to maritime search and rescue incidents, particularly in remote locations. This was confirmed in a 1975 study commissioned by CCG and led to the Canadian Marine Rescue Auxiliary or CMRA being formed in late 1978 as a non-profit organization in an effort to enhance search and rescue coverage and capability, and to better coordinate volunteer efforts. The CMRA was renamed the Canadian Coast Guard Auxiliary or CCGA in 1997.