Nature contact is an emerging health behavior and is defined as the interaction between human beings and animals, plants, natural scenic views, or outdoor activities. Studies have shown that exposure to the outdoors (as a means of contact with nature) reduces perceived stress and promotes health and wellbeing among varying populations in many settings. To date, however, there are few studies exploring the impact of nature contact among college students, especially in the United States. In addition, the determinants of nature contact behavior have not adequately been explored using behavioral theories. The purpose of this study was to use the multi-theory model (MTM) of health behavior change, a contemporary fourth-generation behavioral theory in explaining intentional outdoor nature contact behavior among college students. Using a cross-sectional design, 401 students completed the validated survey based on MTM. Of these, 281 met the inclusion criteria. The mean score for perceived stress based on the Perceived Stress Scale (PSS-10) in the sample was 21.60 (7.08) units, with a possible minimum and maximum scores ranging from 0 to 40 units. Constructs of behavioral confidence (standardized coefficient = 0.591, p < 0.001) and changes in the physical environment (standardized coefficient = 0.271, p < 0.001) from MTM accounted for 57.5% of the variance in the initiation for intentional outdoor nature contact behavior. All the three constructs of MTM—namely, emotional transformation (standardized coefficient = 0.173, p = 0.021), practice for change (standardized coefficient = 0.317, p < 0.001), and changes in the social environment (standardized coefficient = 0.204, p = 0.002)—were statistically significant and contributed substantively toward the variance (31.0%) in sustenance. MTM provides a useful and pragmatic framework for designing interventions to promote intentional nature contact behavior among college students.