Introduction Maintaining physical activity is critical for older people receiving aged care, yet engagement often declines without ongoing support. Wearable activity trackers may provide a scalable strategy to enhance motivation and self-monitoring, but their feasibility and acceptability in aged care settings remain unclear. Methods A mixed-methods feasibility study was conducted with 14 adults aged ≥65 years receiving community or residential aged care services in New South Wales, Australia. Participants used a wrist-worn Fitbit Inspire 3, a smartphone step-counting app, and a linked website over four weeks. Feasibility was assessed through enrolment and retention, while acceptability and usability were evaluated using structured surveys and qualitative feedback. Quantitative data were analysed descriptively, and qualitative data were analysed using inductive content analysis. Results Step tracking was feasible, with 82% enrolment and 93% retention. Participants reported high acceptability, with most indicating increased awareness of physical activity and motivation to move more. The Fitbit was strongly preferred (86%) due to ease of use, comfort, and immediate feedback. Key facilitators included reminders, rewards, and opportunities for social sharing. Barriers included health fluctuations, usability challenges, and occasional technical issues. No adverse events were reported. Conclusion Wearable step trackers are feasible and acceptable for older people receiving aged care and may support behaviour change through enhanced awareness and motivation. Simple, user-friendly designs and supportive features are critical. Larger trials are needed to evaluate effectiveness, long-term adherence, and scalability within aged care systems.