High levels of loneliness are prominent in teenagers ranging from ages 14–19. The 4-week Self-Care program, offered by the Heartfulness Institute, is designed to develop social–emotional skills and self-observation. This study examined the impact of the Self-Care program on loneliness in high school students in the United States in a randomized, wait-list control trial with baseline and postintervention assessments. High school participants, aged 14–19, were randomized into a control-wait-listed group (n = 54) and a Heartfulness group (n = 54). Both the groups completed the intervention and the presurveys and postsurveys online, assessing their loneliness with the UCLA Loneliness Scale. The initial analysis noted the baseline equivalence of the data. A repeated measures ANOVA found a significant time * group interaction, with a significant decrease in loneliness reported in the Heartfulness Intervention group but no significant pre–post difference in the control group. In summary, the short online intervention program consisting of self-care tools decreased loneliness scores in the participants. This study opens up a new valley of possibilities, apart from existing research, and demonstrates that the online intervention used might be helpful to decrease loneliness levels in teens.