Antimicrobial resistance (AMR) is increasingly becoming a threat to global public health, not least in low- and middle-income countries (LMICs) where it is contributing to longer treatment for illnesses, use of higher generation drugs, more expenditure on antimicrobials, and increased deaths attributed to what should be treatable diseases. Some of the known causes of AMR include misuse and overuse of antimicrobials in both humans and animals, unnecessary use of antimicrobials in animals as growth promoters, and lack of awareness among the public on how to protect antimicrobials. As a result, resistant organisms are circulating in the wider environment, and there is a need to consider the One Health approach to minimise the continuing development of AMR. Environmental Health, specifically water, sanitation and hygiene (WASH), waste management, and food hygiene and safety, are key components of One Health needed to prevent the spread of antimicrobial-resistant microorganisms particularly in LMICs and reduce the AMR threat to global public health. The key Environmental Health practices in the prevention of AMR include: (1) adequate WASH through access and consumption of safe water; suitable containment, treatment and disposal of human excreta and other wastewater including from health facilities; good personal hygiene practices such as washing hands with soap at critical times to prevent the spread of resistant microorganisms, and contraction of illnesses which may require antimicrobial treatment; (2) proper disposal of solid waste, including the disposal of unused and expired antimicrobials to prevent their unnecessary exposure to microorganisms in the environment; and (3) ensuring proper food hygiene and safety practices, such as sale and consumption of animal products in which adequate antimicrobial withdrawal periods have been observed, and growing vegetables on unpolluted soil. Environmental Health is therefore crucial in the prevention of infectious diseases that would require antimicrobials, reducing the spread of resistant organisms, and exposure to antimicrobial residues in LMICs. Working with other professionals in One Health, Environmental Health Practitioners have a key role in reducing the spread of AMR including health education and promotion, surveillance, enforcement of legislation, and research.