This thesis argues that the main objective of consumer law is to facilitate consumers’ reflective choices. In order to be reflective, that is autonomy-enhancing, consumers’ choices must meet two conditions. First, they must be accurate, that is consistent with consumers’ preferences. Second, consumers must be able to endorse them after consideration. To this end, consumers should be provided with an opportunity to reflect on their choices and the underlying preferences thereof. Both of these conditions can be compromised in consumer markets, where traders can not only induce consumers to make inaccurate choices, but also have significant power over consumers’ preference-formation. Those circumstances can render consumers’ choices subordinate to traders’ profit-seeking and deprive such choices of their intrinsic, autonomy-enhancing value. Using this framework, the thesis provides an account of European consumer law that is both normatively compelling and descriptively accurate. It interprets the most relevant instruments of the EU consumer acquis – disclosure duties, standard form contracts control, remedies for non-conformity and withdrawal rights – as relatively successful attempts to facilitate consumers’ reflective choices. In doing so, the thesis applies insights from autonomy-based theories of contract law, with modifications where necessary. The thesis goes against the prevalent theoretical perspectives on consumer law in the literature. On the one hand, it opposes the welfarist view, which considers preference-satisfaction as the underlying principle of consumer law. On the other hand, the thesis challenges the instrumentalist approach to European consumer law, focused on facilitating the EU internal market. The main argument of the thesis is then applied to digital consumer markets and the particular challenges they pose. It also responds to the pluralistic challenge, according to which consumers’ autonomy is not the only principle worth pursuing through consumer law.