Despite theoretical accounts asserting the importance of children for the wellbeing of individuals as they age, research evidence suggests that children may be inconsequential when it comes to loneliness. Yet, there is reason to expect some subgroups may be more vulnerable to the impact of childlessness than others and this may also differ depending on the type of loneliness being assessed. This paper addresses the relationship between childlessness and social and emotional loneliness in middle and later life, including differential vulnerability associated with age, gender and marital/partner status. The study drew on data from three waves (2007, 2012 and 2018) of the Canadian General Social Survey for a nationally representative sample of adults aged 45 and older (N = 49,892). In general, childlessness assumed greater importance with regard to social than emotional loneliness. Women reported lower levels of social loneliness in conjunction with childlessness than men. Further, childlessness was associated with higher levels of overall and social loneliness among older than middle-aged adults. Fewer interactions were evident between marital/partner status and childlessness. Among women specifically, those who were co-habiting, separated/divorced or never married reported lower levels of social loneliness than their married counterparts. In contrast, childlessness was linked to greater emotional loneliness only among separated/divorced men and widowed women. Overall, our results suggest that having children available does matter for feelings of loneliness in middle and later life but that the relationship varies and is contingent on the social contexts (age, gender, marital/partner status) and the type of loneliness (social, emotional) involved.