The article reveals the theoretical and practical aspects of the interrelation of social creativity, the demonstration of leadership skills and personal agency of adolescents included in a socially enriched environment of additional education. The methods of studying the development of adolescents' personal agency are described, which make it possible to identify the level of social creativity of an individual and the aptitude of adolescents for leadership. The article presents the results of an experimental study of the dynamics of adolescents' personal agency in connection with the changes in the indicators of their social creativity and leadership potential after the implementation of a specially developed additional educational program "Social testing ground". The obtained results are compared to five stages of the development of personal agency such as "observer", "learner", "apprentice", "master", "creator". A positive growth of the studied parameters among adolescents, the participants of the experiment, has been noted, which allows confirming the conclusion about the systemic nature of personal agency and its interrelation with the creative skills of an individual when interacting with the social environment.