Objective: To determine the relationship between the characteristics and experiences of homeless persons and their state of happiness as a basis for designing appropriate social support strategies. Design: Exploratory observational study with an analytical and descriptive qualitative design. Setting: Participants were contacted, administered with questionnaires, and interviewed in the street (central and northern areas of the city) or at the “Asociación Calor y Café” center in Granada (Spain) between April 2017 and February 2018. Participants: Selected by intentional sampling, 25 participants completed questionnaires in the first study and 14 of these were administered with questionnaires and interviewed in the second study. Method: General and specific questionnaires were administered to determine the state of happiness and other variables. Descriptive statistics were followed by an analysis of the relationships between variables and the content analysis of semi-structured interviews. Results: A feeling of happiness was described by 64% of participants and confirmed by a happiness scale score of 50%. Participants who felt satisfied with their life were 4.5-fold more likely to feel happy (p = 0.021). Expectations for the future were not associated with happiness or satisfaction with life. Content analysis of interviews revealed three main themes: conditions for happiness, own happiness/unhappiness, and self-esteem. Conclusions: Many homeless people describe themselves as feeling happy and satisfied with their life. Material aspects, affective situations, daily life concerns, and self-esteem predominate in their discourse on happiness.