Rapid developments in social networking technologies have led to the increased integration of social media elements in various business operations. Accordingly, online commerce operations have been integrated with social media elements such as ratings, reviews, feedback, and referrals for improving online shoppers’ experience and engagement. This approach of supporting online selling and purchasing activities with the support of social media elements is referred to as social commerce (S-Commerce). The increasing number of internet users, social networking users, and mobile phone users has further contributed to the rise in SCommerce operations. The rapid developments in S-Commerce have led to a related increase in research related to S-Commerce, especially its adoption, the impact of social media elements, and other aspects. However, the impact of culture on S-Commerce operations and users remains largely under-researched. In addition, previous studies have focused on the impact of social constructs such as ratings, reviews, referrals, recommendations etc. Other important factors such as users’ behavioural and psychological constructs, for example motivation, satisfaction etc.; design factors; and the relationship between these factors, remain largely unaddressed. Considering these limitations, this study focuses on identifying the various factors that influence S-Commerce operations and users’ behaviour, the relationship between these factors, and their impact on decision making and purchase intentions on UserCentric S-Commerce Platforms (UCSCPs) in two culturally different countries: Ireland and Saudi Arabia. A User-Centric S-Commerce Framework is derived from the literature, and this is used to develop the platforms for Ireland and Saudi Arabia. Qualitative semi-structured interviews (Phase II), focus groups (Phase I) and quantitative surveys were used to collect the data in two phases (Phase I: gathering user requirements for developing UCSCPs; and Phase II for evaluating the theoretical framework and UCSCPs) from users in both Ireland and Saudi Arabia. Thematic analysis was used to analyse the qualitative data, and statistical techniques including PLS-SEM and Pearson correlational tests were used for the quantitative data analysis. The findings revealed that social constructs, such as reviews, ratings, and referrals; behavioural and psychological constructs including motivation, satisfaction, experience, learnability, and usability; cultural factors including language, celebrity branding, price consciousness, images and videos, and themes can impact users’ trust, and in turn affect the purchase intentions of the users on UCSCPs. In addition, it was identified that culture can impact the relationship between the various factors that influence users on SCommerce platforms. The study findings contribute to the S-Commerce literature. Firstly, the findings contribute to the understanding of critical factors that influence users on S-Commerce platforms. They also identify the relationship between the various factors in S-Commerce that influence decision making and purchase intentions. Lastly, the theoretical contributions of this research are related to the technical, social, cultural, behavioural, and psychological fields, based on the review of SAM, TPB, OLT, UTAUT, and the diffusion of cultural aspects. Similarly, various practical implications can be identified from this study. Firstly, the User-Centric S-Commerce Framework proposed in this study can be used for designing and developing various SCommerce platforms. Secondly, the theoretoical model proposed can help industry practitioners to understand the influence of culture and the relationship between various other factors that influence purchase intentions, enabling them to develop more user-centric platform designs.