Time perspective can shape how individuals experience life, influencing their wellbeing, perspectives and interactions with societal attitudes. This study explores the interconnections between time perspective, perceived ageism and subjective wellbeing (SWB) across the lifespan. Specifically, it aims to (1) compare time perspective, perceived ageism and SWB among three age cohorts across the lifespan; (2) analyse the influence of time perspective on SWB; and (3) examine whether perceived ageism moderates the relationship between time perspective and SWB. Data were collected from 884 Portuguese participants (aged 18–39, 40–59 and 60+) using various methods and subjected to multivariate analyses of variance (MANOVAs) and moderated regression analyses. Findings suggest distinct differences in time perspective, perceived ageism and SWB between the age cohorts. Future FTP-opportunity decreases with age, while FTP-limitation is higher among older adults. Negative and positive ageism are more prevalent among older adults, with positive ageism increasing with age, and satisfaction with life seems to be higher in middle age. Further, FTP-limitation increases negative affect and reduces positive affect and life satisfaction, while FTP-opportunity boosts both of them. Positive and negative ageism moderate these effects, with positive ageism weakening FTP-opportunity’s benefits and negative ageism intensifying its impact on affect and satisfaction with life. Understanding how perceptions of age and future opportunities shape SWB across life stages is crucial. The findings highlight the impact of ageism on both younger and older adults, emphasizing the need for an inclusive approach to age that promotes wellbeing and opportunities for individuals across the lifecycle.