A growing body of research demonstrates the relevance of character strengths for flourishing in general, but also for important outcomes across different life domains (e.g., work performance and relationship satisfaction). Studies have also shown that there are differences in the extent to which character strengths are applied, that is, perceived as relevant and shown in behavior in a given context, between work and private life, but they have not considered other life domains. This study aims to close this gap by examining the life domains of work, education, leisure, close personal relationships, and romantic relationships. The present study investigates whether (a) strengths-related behavior across different life domains explains additional variance in flourishing beyond the trait level of each respective character strength and studies (b) differences in the relevance of character strengths and strengths-related behavior across different life domains, and examines (c) their relationships with flourishing. A sample of 203 German-speaking adults (78.8% females; mean age = 29.4 years) completed self-reports assessing flourishing and character strengths. They also indicated which of the five life domains were personally relevant to them (i.e., on average 4.23 life domains) and reported the character strengths’ perceived relevance and the frequency of displaying strengths-related behavior for each of these life domains separately. The results demonstrate that (a) strengths-related behavior averaged across all relevant life domains explained unique variance in flourishing above the trait-level of character strengths in some cases (e.g., creativity, kindness, and fairness), (b) different life domains were characterized by specific profiles of character strength—regarding both their relevance and strength-related behavior. Moreover, (c) character strengths and strengths-related behavior in different life domains both showed substantial correlations with flourishing. In some cases, these associations were domain-specific (e.g., displaying love of learning in the context of education was related to higher levels of flourishing). In conclusion, we suggest that examining strengths-related behavior across different life domains represents a worthwhile addition to research on character strengths.