In comparison to the general population, military spouses face additional daily challenges to engaging in self-care behaviors like physical activity (PA). PURPOSE: To evaluate the impact of an online intervention specifically designed to address the unique challenges of being a military spouse on spousal PA and mental health. METHODS: A 10-week program entitled Independent but not alone (IBNA) was developed specifically for this population using information from focus groups and through partnerships with individuals in the health/fitness field that are also military spouses. The intervention consisted of weekly podcasts and team challenges designed to facilitate PA, stress management, and social connection among participants. A total of 119 participants (M age = 31.9) for IBNA were recruited from Fort Riley (Junction City, KS). Control group participants were recruited from other military bases around the United States. A total of 112 participants (M age = 33.1) in the control group received links to existing content on the Operation Live Well website. Data were analyzed using mixed design 2 (group) X 2 (time) repeated measures ANOVAs. RESULTS: Participants in both groups reported an increase in total overall PA levels [F(1,152)=12.29, p=.001)], including moderate PA [F(1,152)=14.98, p<.001)], household PA [F(1,152)=15.18, p<.001)], and PA for transport [F(1,152)=4.17, p=0.04)]. Participants also reported positive mental health impacts, including reduced feelings of stress [F(1,149)=52.38, p<.001)], anxiety [F(1,150)=58.29, p<.001)], and depression [F(1,152)=56.94, p<.001)]. The only significant difference between the two conditions was that those in the IBNA group reported a greater level of vigorous PA [F(1,152)=3.98, p=.048)] than those in the control condition. CONCLUSION: Despite few significant differences between groups, there were significant individual level improvements in multiple health outcome measures. These findings suggest that there can be a positive impact on the health of military spouses from tailoring a program to their unique challenges. Future interventions with this population should continue to emphasize the importance of prioritizing self-care and show an interest in meeting the needs of spouses that are often overlooked.