The current research explores the relationship between academic self-concept and locus of control with academic achievement among undergraduate students at Tilka Manjhi Bhagalpur University in Bhagalpur, Bihar. Academic self-concept refers to how students view their academic abilities and potential, while locus of control relates to an individual's beliefs about their control over life events and outcomes. The sample for this study includes 336 students from Marwari and SSV college Kahalgoan, Bhagalpur who are in Part 2. The tools used for this study are Levenson’s Multidimensional Locus of Control and the Academic Self-concept by Liu and Wang (2005). The study employs a descriptive design and data is collected through random sampling. Descriptive, differential, correlation, and regression statistics including Mean, Standard deviation, Standard Error, Pearson’s product-moment correlation, and Student T-Test and Regression analysis are used to analyze the data. The results indicate a significant relationship between academic self-concept and academic achievement among undergraduate students. The study also reveals that internal locus of control is a predictor of academic achievement. Moreover, the combined effect of academic self-concept and internal locus of control is significant on the academic achievement of undergraduate students at Tilka Manjhi Bhagalpur University, Bhagalpur, Bihar.