Whether attending college, entering the workforce, or finding a romantic partner, single emerging adults navigate a pivotal stage of their lives. The present cross-sectional study sought to examine the heterogeneity in happiness of single emerging adults (N = 1,073) with a person-centered, group-differential approach. Using five predictors of life satisfaction (friendship satisfaction, family satisfaction, self-esteem, neuroticism, and extraversion) as indicators in latent profile analysis (LPA), we identified five distinct profiles (or groups) of young singles. The profiles, ordered from favorable to unfavorable indicator patterns, presented diverse shape and level differences that corresponded to varying happiness levels. Singles in Profile 1 with the most favorable indicator patterns (e.g., high friendship satisfaction, low neuroticism) were the happiest, while those in Profile 5 with the least favorable indicator patterns (e.g., low friendship satisfaction, high neuroticism) were the unhappiest. In the middle profiles, singles often offset disadvantages in one area (e.g., high neuroticism) with advantages in others (e.g., high friendship satisfaction) to achieve average to somewhat high levels of happiness. Importantly, friendship satisfaction emerged as a vital indicator, often distinguishing which singles were happy or not. Covariate analyses further validated the profiles and revealed additional profile differences (e.g., gender, anxiety, depression). Overall, our findings underscore the essential role of satisfying friendships in promoting the well-being of single emerging adults.