This study investigated the theoretical and practical relationship between mindfulness and test anxiety. I explored this relationship with college students enrolled in an Introductory Physics II course at a large university in the American Southwest. The goal of this research was twofold: first to explore the theoretical relationship between mindfulness, emotional regulation, attentional regulation, and test anxiety. Second, to examine the effectiveness of using an online-based mindfulness intervention to reduce test anxiety in college students. Results suggest that emotional regulation had very little predictive power while attentional regulation was a strong significant predictor of test anxiety. Additionally, the eight week mindfulness intervention resulted in non-significant changes in test anxiety and quiz scores for the treatment compared to the control. These findings have both theoretical and practical implications.