Aim To provide an overview of public health ethics, how it differs from medical ethics, and why this is important when considering the justification of public health interventions, such as community water fluoridation.Method Narrative review of the literature.Results Like medical ethics, public health ethics is underpinned by moral-based theories: consequentialism and non-consequentialism. Utilitarianism is an example of the former and sees moral action as that which produces the overall greatest benefit or wellbeing in society. In contrast, non-consequentialist theories focus on whether an action is right or wrong regardless of consequences. One such approach is principlism, where respect for autonomy, beneficence (benefit), non-maleficence (avoidance of harm), and justice are considered. However, as most public health interventions restrict autonomy to some extent, these require modification to balance this with any collective benefit. Similarly, political theory influences public health ethical thinking: liberalism's focus on autonomy and avoidance of infringement of freedoms challenges many public health interventions. Given these complexities, frameworks exist to help guide ethical deliberation in public health.Conclusion Various principles and ethical frameworks have been proposed for public health interventions. They have more utility when considering the ethics of interventions, such as community water fluoridation, than those for medical interventions.