The baseline characteristics of employees to predict improvements in healthy lifestyle habits (LHs) following workplace health promotion programs are underexplored. This study sought to identify predictors of improvements in physical activity (PA), eating habits, sleep habits, and stress management, and health risk factors resulting from healthy LHs. The Activate Your Health program included 3 packages of an increasing number of interventions: light, moderate, and high. Participating employees (n = 506) completed baseline and postintervention questionnaires that collected sociodemographic data, health- and LH-related variables, stress-related variables, and perceptions of general health and life satisfaction. Only those with the potential to improve were included in each improvement outcome analysis. Being in high and intending to reduce alcohol consumption increased the odds of improving PA. Very good/excellent perceived general health, poor sleep habits, high alcohol consumption, and intending to improve stress management increased the odds of improving stress levels at work. Depression and intending to improve sleep habits increased the odds of improving stress management. Reporting feelings of pleasure increased the odds of improving body mass index. Baseline characteristics predicting improvements differed for each LH. A targeted approach may be needed to help employees improve LHs and related outcomes.