The purpose of this study is to examine the relationships among self-concept clarity, loneliness, and SNS addiction tendency in female university students and to verify the moderating effect of loneliness on the relationship between self-concept clarity and SNS addiction tendency. The participants were 224 female university students aged 18-28 years enrolled in universities across South Korea, recruited through an online survey. Measurement tools included the Self-Concept Clarity Scale, the Loneliness Scale, and the SNS Addiction Tendency Scale. Data were analyzed utilizing SPSS 27.0 and SPSS PROCESS macro 4.2. The key findings are as follows. First, self-concept clarity, loneliness, and SNS addiction tendency were significantly correlated. Self-concept clarity was negatively correlated with loneliness and SNS addiction tendency, while loneliness was positively correlated with SNS addiction tendency. Secondly, it was found that loneliness moderates the relationship between self-concept clarity and the tendency to become addicted to SNS. This study highlights the interconnectedness of self-concept clarity, loneliness, and SNS addiction tendency, particularly emphasizing the role of loneliness in influencing SNS addiction tendency. These findings provide essential foundational insights into understanding the impact of loneliness on SNS addiction tendency and offer practical implications for the prevention and intervention of SNS addiction tendency among female university students.