Ethical egoism (also called simply egoism) is the normative ethical position that moral agents ought to do what is in their own self-interest. It differs from psychological egoism, which claims that people can only act in their self-interest. Ethical egoism also differs from rational egoism, which holds merely that it is rational to act in one's self-interest. Contractual egoism acknowledges the interdependence of self-interests through voluntary, freely chosen exchanges. These doctrines may, though, be combined with ethical egoism.

Ethical egoism contrasts with ethical altruism, which holds that moral agents have an obligation to help and serve others. Egoism and altruism both contrast with ethical utilitarianism, which holds that a moral agent should treat one's self (also known as the subject) with no higher regard than one has for others (as egoism does, by elevating self-interests and "the self" to a status not granted to others), but that one also should not (as altruism does) sacrifice one's own interests to help others' interests, so long as one's own interests (i.e. one's own desires or well-being) are substantially equivalent to the others' interests and well-being. Egoism, utilitarianism, and altruism are all forms of consequentialism, but egoism and altruism contrast with utilitarianism, in that egoism and altruism are both agent-focused forms of consequentialism (i.e. subject-focused or subjective), but utilitarianism is called agent-neutral (i.e. objective and impartial) as it does not treat the subject's (i.e. the self's, i.e. the moral "agent's") own interests as being more or less important than the interests, desires, or well-being of others. Although the utilitarian concept of enlightened self-interest could be considered an agent-focused form of the philosophy.