Objective. To determine the relationship between digital marketing and customer loyalty in the development of commercial sustainability in the province of Tarma, Junín region (Peru). Methods. The research had a quantitative approach and was of basic type, correlational level and non-experimental-cross-sectional design; two instruments were used: the digital marketing questionnaire and the customer loyalty questionnaire. The first questionnaire consisted of 12 items referring to the dimensions of digital marketing and the second consisted of 15 items referring to the dimensions of customer loyalty. The sample consisted of 120 customers of commercial establishments in the province of Tarma. Results. 47.5 % of respondents considered that the implementation of digital marketing in commercial establishments is regular, 36.7 % considered that there is a low implementation and only 15.8 % cons...