Digitalization and the rapid development of society determine the need to adapt legislation and law enforcement practice to the requirements of the digital age. Antitrust policy is also changing and developing tools that allow timely response to the challenges of the digital economy. One such tool is behavioral economics, which is becoming increasingly important in today’s digital environment, and allows regulators to be flexible and contribute to the achievement of the main goals of competition law — to maintain a competitive state of the market and avoid the concentration of excessive power in the hands of one economic entity. The practice of applying behavioral economics by antitrust authorities is becoming more extensive, as there is a large pool of data in the digital environment, including information about consumers, which can be used by companies to influence users, as well as lead to unfair competition. Thus, the paper will study the issue of using behavioral economics in terms of consumer choice by antitrust authorities in order to identify possible behavioral insights of consumers that affect the correct establishment of product markets and the identification of competition law violations by companies. Applying the legal doctrinal approach, the descriptive method, and the comparative law method makes it possible to establish the issue’s relevance in different countries and the prospects and trajectories of the usage of behavioral economics in antitrust practice. As a result of the study, a global trend has been established in the application of behavioral economics by antitrust authorities both in determining the boundaries of commodity markets and in detecting violations of antitrust laws. It is concluded that the use of such a tool will continue, as it contributes to the timely adaptation of existing antitrust laws to the challenges of the digital age, contributes to the achievement of competition law goals, and creates a thriving competitive environment.