This study aimed to explore the sources of happiness of individuals across different stages of their lives. A phenomenological study, which is a qualitative research approach, was designed. The sample consists of 129 participants (62 women, 67 men). Thematic analysis was conducted to analyze the data, and common themes were identified for each life stage. The analysis of the themes revealed that children and adolescents expressed the sources of happiness mostly through hedonic values, whereas individuals in middle adulthood and late middle age predominantly expressed them in eudaimonic values. Sources of happiness in all life stages include the themes of closeness to family, closeness to friends, social relations, altruistic attitudes, social peace, and traveling. In young adulthood and later life stages, the theme of spirituality emerged, including concepts such as the meaning and purpose of life, belief in God, gratitude to God, and being connected with nature. In childhood, the themes of playing games, receiving gifts, and experiencing surprises were prominent sources of happiness, whereas in adolescence, the themes were eating favorite things and achieving autonomy. Health, money, being successful, hope, hobbies, being valued and appreciated were found to be other common sources of happiness across various life stages.