Beginning college involves changes that can increase one's vulnerability to loneliness and associated negative outcomes. Parent and friend relationships are potential protective factors against loneliness given their positive association with adjustment. The present longitudinal study, with data collection at baseline, 1 month, and 2 months later, assessed the comparative effects of self-reported parent and friend relationship quality on loneliness in first-year college students (N = 101; 80 female, M_age = 18.36). At baseline, parent and friend relationship quality were negatively associated with loneliness. Longitudinal data revealed that friend relationship quality interacted with time, such that its effects on loneliness attenuated over the course of 2 months. By contrast, parent relationship quality continued to predict lower loneliness 2 months post-baseline. These results highlight the importance of close relationships and suggest that targeting relationship quality could be effective in helping youth transition to college.