Consent, in terms of voluntary choice, is - or, at least, appears to be or purports to be - at the essence of contract law. Contract law, both in principle and in practice, is about allowing parties to enter arrangements on terms they choose - each party imposing obligations on itself in return for obligations another party has placed upon itself. This freedom of contract- an ideal by which there are obligations to the extent, but only to the extent, freely chosen by the parties - is contrasted to the duties of criminal law and tort law, which bind all parties regardless of consent. At the same time, consent, in the robust sense expressed by the ideal of freedom of contract, is arguably absent in the vast majority of the contracts we enter these days, but its absence does little to affect the enforceability of those agreements. Consent to contractual terms often looks like consent to government: present, if at all, only under a fictional (as if) or attenuated rubric. This article explores a variety of topics relating to consent, and the role it plays in contract law doctrine and theory. The article begins by a brief examination of the nature of consent, then turns to contract doctrines that turn on the alleged absence of consent (e.g., duress and undue influence); contract rules and principles (e.g., implied terms) that turn on hypothetical consent; the challenges to consent that arise from electronic contracting and bounded rationality, and theories of contract law that emphasize consent.