The Marine Animal Response Society (MARS) is a Canadian conservation organization and registered charity dedicated to protecting marine life, supporting ocean health, and engaging communities in stewardship. Based in the Maritime Provinces, MARS coordinates responses across Nova Scotia, New Brunswick, and Prince Edward Island through a toll-free emergency hotline staffed year-round. Its team and volunteer network assist with incidents involving stranded whales, injured seals, entangled sharks, sea turtles, and other marine animals, prioritizing animal welfare and the safety of responders and the public.

MARS also conducts research by studying reported animals and collecting data and samples to better understand marine health and threats such as pollution, vessel strikes, entanglement, and climate change. Its MARS Lab, a dedicated marine animal necropsy facility, supports investigations into causes of death and wider research on ocean health. The organization contributes to conservation advocacy and policy, provides community education and engagement opportunities, and builds response skills through training, including its internationally recognized Marine Animal Medic Course.