This chapter evaluates the relationship between the United Nations Commission on International Trade Law (UNCITRAL) and the Hague Principles. The UNCITRAL texts, starting with the early drafts of the United Nations Convention on Contracts for the International Sale of Goods (CISG), have provided solid ground in support of freedom of contract. In providing a uniform model applicable to multiple jurisdictions, the CISG ensures a high level of safeguard of parties’ wills. In particular, the CISG promotes the well-established principle of party autonomy by virtue of its Article 6, which allows parties to the contract to opt out entirely of its provisions and hence to choose another law more appropriate to their needs. Given UNCITRAL’s desire to further facilitate use of the CISG by traders and in light of its focus on freedom of contract and party autonomy, it is not surprising that the UNCITRAL Secretariat took a particular interest in the development by the Hague Conference on Private International Law of the Principles on Choice of Law in International Commercial Contracts (2015) and the related Commentary. The chapter then looks at UNCITRAL’s endorsement of the Hague Principles.