Age-Friendly Cities (AFC) is a framework for promoting healthy ageing through local actions. We use systems thinking to assess potential outcomes of actions to support older people's mobility, undertaken within an AFC commitment in Greater Sydney. Interviews with 20 informants involved in providing space, infrastructure, or services that affect how older people get around were analysed using causal loop diagrams (CLDs). Four approaches to support older people's mobility were identified and situated to the Multiple Governance Framework: land use, open and public space, supplementary transport, and community transport. Analysis revealed potential for unwanted consequences associated with each, which can be generalised into three generic potential outcomes for other jurisdictions to consider. A recommendation from this research is for policy actors to examine feedback interactions between actions so that they can foresee a wider range of outcomes and take defensive action against those unwanted. By situating CLDs within the Multiple Governance Framework, this research not only identifies what to look for, in terms of potential outcomes, but also where to look, in terms of the level of decision-making. This research offers a new way to assess the functioning of AFC governance networks by their collective outcomes and challenges the standards for the evaluation of AFC.