<p>Research on student experiences of the impostor phenomenon (IP) in academia has grown significantly over the last 40 years; however, several gaps remain in the literature, particularly concerning which groups are most affected and how IP impacts broader measures of wellbeing. The present study investigated impostor feelings using an online survey with a sample of 1655 students at a Canadian university, focusing on group comparisons between heterosexual and LGBTQ+ students, between non-racialized and racialized students, and between men and women. A serial mediation model was tested to determine whether self-efficacy and resilience mediated the relationship between IP and life satisfaction, and whether this model was relevant across different groups. As hypothesized, there was statistical support for the serial mediation model from IP through self-efficacy and resilience to satisfaction with life. Students who identified as LGBTQ+, racialized, and women reported higher IP scores than their non-marginalized peers. The mediation model was statistically supported within the overall sample and demonstrated a similar pattern of associations across groups. Findings for gender were less consistent, with the mediation model reaching statistical significance among male students. These results highlight the importance of tailored approaches and interventions to address impostor feelings and build wellbeing in academia, particularly for LGBTQ+ and racialized students.</p>