Loneliness has steadily increased over several decades, disproportionately impacting young adults, with 79% of 18–24-year-olds feeling lonely. Social media sites have been used for social connections; however, despite the perceived social aspect, excessive social media use (ESMU; i.e., 2+ hours/day) can reduce in-person social interactions. There are conflicting results about the social benefits that young adults obtain through social media use. The objective of this study was to explore the association between social media use and loneliness among U.S. college students. A secondary analysis of the Fall 2022 and Spring 2023 American College Health Association’s National College Health Assessment data including 64,988 college students ages 18–24-years was performed. Social media use was measured using an 8-category variable of the hours/week spent on social media. Loneliness was measured using the 3-item UCLA loneliness scale, which was categorized into two categories: (1) negative for loneliness (3-5 scale score) and (2) positive for loneliness (6-9 scale score). An adjusted logistic regression model was fitted including the covariates of student age, sex, race/ethnicity, year in college, enrollment status, course format, college housing, sorority/fraternity involvement, and parent education level. Over half (54.1%) of the college students were positive for loneliness. About 13% of college students reported using social media sites for ≥16 hours/week. Compared to college students who reported 0 hours/week on social media, college students who used social media for 16-20 hours/week (adjusted odds ratio [AOR]=1.19, 95% confidence interval [CI]=1.09-1.31), 21-25 hours/week (AOR=1.23, 95%CI=1.10-1.38), 26-30 hours/week (AOR=1.34, 95%CI=1.16-1.55), and ≥30 hours/week (AOR=1.38, 95%CI=1.20-1.59) were significantly more likely to report loneliness while adjusting for the covariates, respectively. Findings suggest a potential dose-response association between frequency of social media use and loneliness among U.S. college students. Because participants reporting ESMU (i.e., ≥16 hours/week on social media) had the highest odds of loneliness, further research is needed to assess the bi-directional and potentially recursive nature of this relationship. Efforts should also examine the mental health and behavioral drivers and consequences of ESMU among college students.