<p>The widespread use of social media increases the likelihood of exposure to materialistic content, prompting extensive research into the relationship between social media use (SMU) and materialism. However, a comprehensive quantitative synthesis of this relationship remains lacking. This study conducted a systematic review and three-level meta-analysis to examine the association between SMU and materialism, and to assess whether the association varies across SMU types, materialism measurements, and sample characteristics. A total of 55 studies, encompassing 90 effect sizes and 28,531 participants, were included through a systematic literature search. The results showed a significant positive association between SMU and materialism (<i>r</i> = 0.322). SMU type, culture, and materialism measure significantly moderated this association, whereas country income, gender, and age were not significant moderators. These findings highlight the need to consider measures that promote diverse, non-materialistic social media content and enhance users’ media literacy, which may help mitigate materialistic orientations.</p>