Multilateral arbitrations, due to the complexities arising from multiple parties and the existence of numerous contracts, often encounter specific and multifaceted legal challenges. In this context, the estoppel principle can play a pivotal role in overcoming obstacles in resolving multilateral disputes—particularly where arbitration agreements are not identical or similar, yet the disputing party has participated in the performance of the contract and benefited from its advantages. Consequently, at the time a dispute arises, the party cannot refuse participation in related multilateral arbitration proceedings on the basis of the nature of arbitration or lack of consent. Although similar concepts to the estoppel principle exist in Roman-Germanic law, such as equity and good faith, the principle is especially invoked where a non-contracting party has benefited from a contract and is required to participate in a single arbitration. This ensures that all related disputes are addressed in a centralized multilateral arbitration. This article, through an examination of judicial practice and relevant legal principles, demonstrates how the estoppel principle—relying on fairness and efficiency—can facilitate the equitable resolution of complex commercial disputes, while addressing third-party objections and overcoming various obstacles, including the parties’ consent and the arbitral tribunal’s jurisdiction.