Abstrak − Diabetes Melitus merupakan penyakit metabolik kronis yang ditandai dengan tingginya kadar gula darah akibat gangguan produksi atau penggunaan insulin. Penelitian ini bertujuan mengembangkan model klasifikasi otomatis untuk mendukung diagnosis dini menggunakan algoritma Light Gradient Boosting Machine (LightGBM) dengan optimasi hyperparameter tuning Optuna. Beberapa skenario eksperimen dilakukan, meliputi baseline LightGBM, LightGBM dengan Optuna, serta kombinasi dengan Synthetic Minority Oversampling Technique (SMOTE) pada data latih dan keseluruhan data untuk mengatasi ketidakseimbangan kelas. Evaluasi model menggunakan metrik akurasi, presisi, recall, F1-score, dan AUC. Hasil menunjukkan bahwa skenario LightGBM + Optuna + SMOTE pada data latih memberikan keseimbangan terbaik dengan akurasi 96,82% dan AUC 0,9743, serta peningkatan recall pada kelas minoritas. Model terbaik kemudian diintegrasikan ke dalam platform berbasis web sebagai sistem pendukung diagnosis dini. Penelitian ini membuktikan bahwa optimasi hyperparameter dan penyeimbangan data berkontribusi signifikan terhadap peningkatan kinerja klasifikasi Diabetes Melitus.Kata Kunci: Diabetes Melitus; LightGBM; Optuna; SMOTE; Machine Learning; Abstract − Diabetes Mellitus is a chronic metabolic disease characterized by high blood glucose levels due to impaired insulin production or utilization. This study aims to develop an automated classification model to support early diagnosis using the Light Gradient Boosting Machine (LightGBM) algorithm with hyperparameter optimization via Optuna. Several experimental scenarios were conducted, including baseline LightGBM, LightGBM with Optuna, and combinations with the Synthetic Minority Oversampling Technique (SMOTE) applied to both the training data and the entire dataset to address class imbalance. Model performance was evaluated using accuracy, precision, recall, F1-score, and Area Under the Curve (AUC). The results demonstrated that the LightGBM + Optuna + SMOTE on training data achieved the best balance, with an accuracy of 96.82% and an AUC of 0.9743, while also improving recall for the minority class. The best-performing model was then integrated into a web-based platform, making it accessible to medical professionals and general users as a decision-support tool for early Diabetes Mellitus detection. This study highlights that hyperparameter optimization combined with data balancing techniques can significantly enhance classification performance.Keywords: Diabetes Mellitus; LightGBM; Optuna; SMOTE; Machine Learning;