I defend the claim that every individual must have existed; or, in other words, that every individual is a necessary existent. Henceforth, I shall take the expression 'necessary existence' to abbreviate this claim, and I shall take 'contingent existence' to abbreviate the negation of this claim. In order to defend necessary existence, I clarify what I mean by 'exists'. I argue that there are many different senses of 'exists', and exactly one of these senses is appropriate for the purposes of philosophical logic and modal metaphysics. Making essential use of this sense of 'exists', I defend necessary existence against various objections embodied in several arguments for contingent existence. Having responded to these arguments, I then outline the requirements for a convincing case for necessary existence. Specifically, I argue that a metaphysical case must be made for the acceptance of this claim. This metaphysical case for necessary existence is embodied in an argument I present from the metaphysics of propositions. The premises of this argument concern the conditions under which a proposition is true and a proposition exists. Given these premises, it follows that everything is a necessary existent. I defend this argument from a number of objections to the metaphysics of propositions presented here. I then present and defend three arguments from formal, logical considerations for necessary existence. These three arguments make use of three common axioms or rules of inference. I defend each of these three principles from the objections posed by Saul Kripke, Kit Fine, and Arthur Prior. I then defend necessary existence from the challenges posed by Alvin Plantinga's modal theory of essences, David Lewis's counterpart theory, and Alan McMichael's role semantics. This completes my defence of the three arguments from formal considerations and the argument from metaphysical considerations.