Background: Non-alcoholic fatty liver disease (NAFLD) is a common liver condition that has gained significant attention due to its increasing prevalence worldwide, including Northeast India.Urban dietary patterns, sedentary lifestyle, and sleep disturbances have been associated with the development and progression of NAFLD. Disruptions to circadian rhythms, including irregular sleep patterns, are emerging as critical factors influencing metabolic disorders like NAFLD. Aim: This study aims to explore the role of biological clock disturbances and lifestyle factors, including sleep quality and physical activity, in managing NAFLD among individuals in Northeast India. Methods: A cross-sectional study was conducted among 157 participants diagnosed with NAFLD at Gauhati Medical College and Hospital, Guwahati, Assam. Data was collected through structured interviews, clinical assessments, and diagnostic tests, including liver enzyme tests and abdominal ultrasound. Participants were assessed for circadian rhythm disturbances, sleep quality (using the Pittsburgh Sleep Quality Index), lifestyle factors, and liver function markers. Descriptive statistics, Pearson correlation, and multivariate regression analysis (SPSS version 23.0) were used to analyze the data. Results: The study found that 62.4% of participants exhibited poor sleep quality, and 59.2% followed a sedentary lifestyle. Poor sleep quality was significantly correlated with elevated liver enzymes (ALT and AST) and higher BMI (p < 0.05). Multivariate regression analysis revealed that circadian rhythm disruption and physical inactivity were independent predictors of moderate-to-severe NAFLD (β = 0.36, p < 0.01). Conclusion: The study highlights that biological clock disturbances, including poor sleep quality and sedentary behaviour, play a significant role in the progression of NAFLD in Northeast India. The findings suggest that lifestyle interventions aimed at improving sleep quality and physical activity may help in managing NAFLD and improving metabolic health. Recommendations: Future interventions in Northeast India should focus on promoting better sleep hygiene, reducing sedentary behaviour, and aligning eating patterns with natural circadian rhythms to prevent or manage NAFLD. Further longitudinal studies are recommended to explore the long-term effects of these interventions.