Introduction: Contributing to society constitutes an essential part of healthy ageing. To date, however, it remains unclear how valuable contributions such as caregiving and volunteering, also described as unpaid productive activities, are related to older adults’ loneliness. The present longitudinal study addresses this question in a lower-middle-income country, in Indonesia. Methods: Using data from two waves of the nationally representative Indonesian Family Life Survey (2000–2014), logistic regression models were applied with caregiving (to non-resident children, siblings, and parents) and volunteering (1–99 h, >100 h per year) as predictors and loneliness as outcome. Participants who were <50 years old and felt lonely at baseline were excluded. Results are reported as odds ratios (OR) and 95% confidence intervals (CI). Results: Of the 3,572 participants (52.8% women; Mean age: 60 years), 538 (15.1%) developed loneliness. In the unadjusted model, volunteering 1–99 h per year and caregiving to parents were each associated with a lower likelihood of feeling lonely later in life. For moderate volunteering (1–99 h), participating in the volunteer decision-making process was beneficial for loneliness. After adjusting for covariates, only the association between caregiving to parents and loneliness remained significant (OR=0.48, 95%CI: 0.27–0.81, p = 0.01). Specifically, providing care to parents who did not need help with daily activities was associated with lower loneliness. Conclusion: This longitudinal study addresses important research gaps in the literature on global healthy ageing, as it relates to the protective role of older adults’ unpaid productive activities on loneliness in Indonesia.