In this study, we aimed to explore the effects of Internal/Chance/Powerful Others Health Locus of Control (IHLC/CHLC/PHLC) on the healthy lifestyle and to assess the sensitivity of the healthy lifestyle to sociodemographic variables. To achieve this goal, we collected data by performing online and hand-delivered surveys ( n = 950) with individuals aged 18 or older in Türkiye. The results showed that IHLC and PHLC had positive and significant effects on Healthy Lifestyle Index (HLI). However, the results expressed that CHLC had no negative and significant effect on HLI. Our assessment of a healthy lifestyle in terms of health locus of control (HLC) and sociodemographic variables revealed important findings, which may contribute to the development of public health strategies in several ways; for example, they can be used as a framework to conduct public health interventions that promote a healthy lifestyle.