It is well known that negative ageing perceptions have various detrimental effects on indicators of successful ageing, but less is known about the role of social support networks and loneliness in ageing perceptions. The objective of this study was therefore to assess the association of social networks, relationship quality and loneliness with negative ageing perceptions in late life. Cross-sectional data on 6,912 adults aged ⩾50 years from the first wave of the Irish Longitudinal Study on Ageing (TILDA) were analysed. Ageing perceptions were assessed with the Brief Ageing Perceptions Questionnaire. Information on social support networks, loneliness and socio-demographics were obtained using standard questions. Depressive symptoms were assessed with the Center for Epidemiologic Studies Depression scale. Multivariable linear regression was conducted to assess the associations. Social isolation, poor relationship quality (with spouse, children, other family members or friends) and loneliness were all significantly associated with negative ageing perceptions even after adjustment for all potential confounders including depressive symptoms. Our study indicates that targeting integration into social support networks and improving relationship quality may potentially reduce the extent to which older individuals adopt negative ageing perceptions. Future studies with prospective design are warranted to understand the temporal direction and causal association of social support networks and loneliness with negative ageing perceptions.