Accurate predisposition assessment is essential for the prevention and early detection of diseases. Polygenic scores and machine learning models have been developed for disease prediction based on genetic variants and other risk factors. However, over 80% of genomic data were acquired from individuals of European descent. Other ethnic groups comprise the vast majority of the world population and have a severe data disadvantage. Due to the lack of suitable training data, clinico-genomic risk prediction is less accurate for the non-European population. Here we employ a transfer learning strategy to improve the clinico-genomic prediction of disease occurrence for data-disadvantaged populations. Our multiethnic machine learning experiments on real and synthetic datasets show that transfer learning can significantly improve disease prediction accuracy for data-disadvantaged populations. Under the transfer learning scheme, the prediction accuracy for the data-disadvantaged populations can be improved without compromising the prediction accuracy for other populations. Therefore, transfer learning provides a Pareto improvement toward equitable machine learning for genomic medicine.