Digital phenotyping and machine learning technologies have shown the potentials to measure objective behavioral and physiological markers, provide risk assessment for people who might have a high risk of poor mental health and wellbeing, and help better decisions or behavioral changes to support health and wellbeing. I will introduce a series of studies, algorithms, and systems we have developed for measuring, predicting, and supporting personalized health and wellbeing. I will also discuss challenges, learned lessons, and potential future directions in mental health and wellbeing research.