Background: Fear of missing out (FoMO) and homesickness have been associated with a variety of negative psychosocial outcomes; however, they have rarely been studied together or with adolescents in residential settings. Objective: This study examined the potential associations of FoMO and homesickness with program outcomes in a sample of adolescents attending a military-style residential program. The residential treatment context inherently involves removal and isolation from an individual's typical living arrangements. Methods: Data were collected from 185 participants (aged 16-18) at three time points (i.e., 2 weeks after entry into the 19-week program; 9 weeks into the program; at week 18 of the program). RESULTS: Overall, FoMO and homesickness declined from initial assessment to midway through the program but rebounded just prior to exit from the program. FoMO and homesickness showed no direct correlations with participant outcomes, although both showed patterns of correlation demonstrating poor adjustment (e.g., low emotion regulation, high loneliness). Decreases in FoMO and homesickness during the program were positively correlated with distress tolerance. Conclusions: Given the negative implications of experiencing FoMO and homesickness, adolescents at risk for emotional distress tolerance may need additional support when initiating participation in residential programs.