Loneliness and social isolation represent persisent global public health concerns, particurarly for people in later life, with extensive mental, social, and biological consequences. Both have been associated with increased risk of depression, anxiety, dementia, cardiovascular disease, premature mortality, and greater demand for health and social care services. A growing body of evidence indicates that nature-based interventions are effective in reducing loneliness, enhancing mood, and promoting overall well being, yet they still remain underutilised within health and social care strategies; particularly for older adults and those with limited mobility. One such initiative, Cycling Without Age, a grassroots programme, demonstrates the potential of nature-based interventions. Evidence across multiple contexts indicates improvements in mood, life satisfaction, and social connectedness, alongside benefits for families and care staff. Cycling Without Age illustrates a type of scalable, person-centred intervention that could be integrated into healthy ageing strategies. However, rigourous large-scale research remains scarce, which highlights the need for further evaluation to guide policy adoption and sustainable implementation. Effective responses to loneliness and social isolation require integrated support programmes that foster social connectedness and healthy ageing, delivered through coordinated efforts spanning public health, urban design, and community services.