Singapore's courts have long refused to adopt proportionality review in constitutional adjudication. However, their instinct to reject proportionality, while possibly well-founded, has yet to be thoroughly tested. This article forwards three arguments for proportionality's use in Singaporean constitutional adjudication. First, as a matter of precedent, proportionality's four enquiries are already latent in Singapore's constitutional jurisprudence. Second, as a matter of principle, Singapore's courts have the constitutional authority to adopt proportionality as a ground of constitutional review and are not institutionally incompetent to answer its enquiries. Third, on grounds of policy, proportionality is desirable because it helps ensure the cogency and rationality of legislative or executive acts within Singapore's burgeoning political culture of justification. By making a case for proportionality in precedent, principle and policy, this article hopes to initiate a considered discussion on whether and, if so, to what extent proportionality should be used in Singaporean constitutional adjudication.