Purchasing decision has an important meaning for companies because it can increase sales and profits. Companies must also retain their customers in order to companies can save costs or spend a little money to find new customers. Besides, old customers also have positive experiences with companies that can also recommend the company to their friends or relatives in their environment. The purpose of this study was to determine the effect of influencer marketing, product quality, and price on youth online shop fashion products in Purbalingga. This type of research is quantitative research. The sampling technique used is purposive sampling technique with sample criteria, namely teenagers who live in Purbalingga who are active on social media and follow an influencer until they have made a fashion purchase at an online shop because they are influenced by the influencer. Primary data obtained in this study using a questionnaire totaling 114 respondents. The data analysis techniques used in this research are descriptive statistics, instrument testing, classical assumption test, multiple linear regression analysis, coefficient of determination test, F test and hypothesis test (t). based on the results of data analysis shows that the influencer marketing variable partially does not have a positive and significant effect on purchasing decisions. While the product quality and product price variables partially have a positive and significant effect on purchasing decision.