The article deals with the problems of organizing an information-educational environment as an essential condition for formation of ICT competence of future mathematics teachers. Global trends of the transition to the information economy influence the importance of this problem and Ukrainian society does not stand aside from these processes. The formation of a professional specialist that is competent in a particular area begins at school. A competent ICT teacher has more opportunities to build appropriate skills of his students. Currently, problems of using the information-educational environment in the educational process were analyzed in the scientific works of V. Bykov, R. Gurevich, M. Kademii, I. Zakharova, I. Robert and others. At the same time, the problem of creating and functioning of an information-educational environment in the formation of ICT competence of future mathematics teachers in the process of training is not sufficiently studied. The aim of the article is a theoretical justification of the importance of creating and functioning of an information-educational environment in the formation of ICT competence of future mathematics teachers. Research results. To fulfill the tasks of building ICT competence, certain conditions must be created artificially, including the information-educational environment. The study proposes the definition of the information-educational environment as a purposefully built complex consisting of information resources, technical means of processing, methods for obtaining, analyzing, systematizing, creating, presenting, applying, processing information in a holistic systemic form, which allows the educational process to be more intensive, as a result the functioning of the pedagogical process becomes more effective. Its structural elements and characteristic features are determined Conclusions and prospects for further research. The availability of the information-educational environment for the formation of ICT competence of mathematics teachers simultaneously ensures the formation of theoretical knowledge and practical skills, and creates prerequisites for the development of professional skills that are necessary for professional growth.