This research intends to critically assess the influence of social media on younger generation online purchase behavioural changes in the digital era. The study focused on the core problem of how social media significantly influences young generation people's purchasing attitudes towards online buying decisions. The descriptive research design assesses the young generation's attitude and behavioural characteristics. To obtain data from the samples, the quantitative research methodology of survey study was utilized (N = 130). Non-probability categories of convenience sampling techniques were used to draw the study sample, and the research was carried out among the younger generation people in Greater Chennai Corporation in Tamil Nadu State. The survey study questionnaire focuses on participants’ socio-demographics and online purchasing behaviour-related variables; the study's primary data were collected through an online Google Form. To obtain the results, the descriptive and regression analyses were utilized for the demographics and online buying activity aspects of the respondents. This study finding revealed that the social media apps on Instagram and YouTube have a greater impact on changing the young generation's online purchasing decisions. The study also highlighted that social media celebrity influencers and product content, online reviews, ratings, and recommendations were the key factors influencing their online purchasing decisions towards the young generation. Additionally, the variables such as family monthly income had an insignificant effect on buying behavior. This suggests that while financial status may play a role in overall spending habits, it does not significantly affect the influence of social media on purchasing choices among the youth. Ultimately, the findings underscore the importance of digital marketing strategies that leverage social media platforms to engage and inform young consumers.