The International Union for Conservation of Nature assesses the orca's conservation status as data deficient because of the likelihood that two or more killer whale types are separate species. Some local populations are considered threatened or endangered due to prey depletion, habitat loss, pollution (by PCBs), capture for marine mammal parks, and conflicts with human fisheries. In late 2005, the southern resident killer whales, which swim in British Columbia and Washington state waters, were placed on the U.S. Endangered Species list.

Wild killer whales are not considered a threat to humans, and no fatal attack on humans has ever been documented. There have been cases of captive orcas killing or injuring their handlers at marine theme parks. Killer whales feature strongly in the mythologies of indigenous cultures, and their reputation in different cultures ranges from being the souls of humans to merciless killers.