Background: Quality of life is one of the most important conceptual categories in many scientific fields and socio-economic practices. In the authors’ opinion, the assessment of the overall quality of life and the health-related quality of life of private entrepreneurs deserves particular attention. Until now, quality of life and its determinants in entrepreneurs have been investigated by few authors. The aim of this study was to identify and assess the key determinants of quality of life and its health-related aspects in entrepreneurs from Wroclaw, Poland. Methods: A questionnaire survey was carried out in a group of 616 entrepreneurs selected from among 4332 individuals (2276 women, 2056 men) who had participated in a study on the socioeconomic determinants of quality of life and physical activity of Wrocław residents of working age. The main research method was a diagnostic survey using S-ES and WHOQOL BREF questionnaires. Information was obtained on respondents’ quality of life and perceived health condition, as well as sex, age, education, marital status, number of people in the household, income per capita, savings, and indebtedness. The collected data were subjected to statistical analysis using numerical distribution, medians, and quartile deviation. Crude and adjusted odds ratios were used to assess relationships between entrepreneurs’ quality of life and socioeconomic status. Results: Over 66% of Wroclaw entrepreneurs rated their overall quality of life as average or above average and about 34% as below average. An average or above assessment of perceived health condition was provided by 71% of respondents, and below average by 29% of respondents. Health-related quality of life was assessed as average or above average in the environmental domain by 79%, physical domain by 77%, social domain by 65%, and psychological domain by 58% of the entrepreneurs. Among the respondents significant correlations were found between quality of life and perceived health condition; family status, i.e., marital status; number of persons in the household; and financial status, i.e., per capita income, savings, and debt. Conclusions: The results of this study can be used for managing the quality of life of entrepreneurs. Quality of life determinants should be constantly updated, as they may change along with further economic development and Poland’s economic convergence with better developed EU countries.