Supporting older adults’ health and well-being in the transition from work to retirement requires a holistic perspective and needs to address physical, mental, and social aspects of life. In a field study, applying a mixed-methods approach, we investigated to what extent the prototype of a digital coach can support older adults in this sensitive phase. We aim at answering the central research question: How can a digital coach support older adults in the transition from work to retirement to establish and maintain a healthy lifestyle? Overall, 32 participants from Austria and Belgium took part in an eight-week trial. App-based interventions in different domains (physical, mental, social) were provided and aimed at motivating the target group to become and/or stay active. The study shows that the digital coach has potential to support health and well-being on various levels. In particular, the mental activities proofed valuable and supported older adults’ well-being.