Can selfishness be benevolent?
Yes. In fact, genuine benevolence depends on a rationally self-interested base. If "selfishness" means predation, entitlement, or using other people as disposable tools, then no. But that is not real selfishness. Rational self-interest means serious concern for your own life, values, character, and long-term flourishing.
A person who knows their own worth does not need to buy moral approval through sacrifice. They can care about friends, a spouse, children, clients, collaborators, and strangers without treating their own life as the price of admission. Other people can be real or potential values: sources of love, trade, learning, admiration, companionship, shared work, and joy.
This is why benevolence is strongest when it is voluntary and reality-based. If you give because you value the person, the relationship, the project, or the kind of world you are helping make possible, the action thereby serves your life, too. If you give because you are afraid of being judged, because you feel unworthy, or because someone demanded your values as a moral debt, that is not benevolence. It is appeasement, guilt-management, or self-erasure.
This also fits the broader harmony of genuine human interests. In the long run and full context, healthy relationships are not built on one person winning by draining the other. The right aim is not "me or you", but a relationship in which both people can prosper without coercion, manipulation, unearned guilt, or sacrifice.
The practical test is simple: Does this act of goodwill come from strength, choice, and real value? Or does it come from fear, shame, pressure, or a demand that you give up what matters most? Benevolent selfishness is kindness without self-erasure. It is goodwill with self-esteem, boundaries, and integrity.