Objectives This study examined the association between perceived manageability of debt and risk of depression, anxiety, and mental health help-seeking among a nationally representative sample of adults living in the United Kingdom (UK). Methods Data was derived from the COVID-19 Psychological Research Consortium (C19PRC) Study Wave 6 (August/September 2021) which examined the psychological, social, and economic effects of the COVID-19 pandemic on the UK adult population. Bivariate and logistic regression analyses were conducted to determine the association between different levels of perceived debt manageability (i.e., “easily manageable”, “some problems”, “quite serious problems”, “very serious problems”, “cannot manage at all”) and mental health related outcomes. Results Almost a quarter of the sample (24%, n = 494) reported debt management problems, and debt manageability associated with higher levels of anxiety, depression, and mental health help-seeking. After adjusting for demographic variables (e.g. income, receipt of benefits), logistic regression analysis demonstrated a dose-response association between increasing levels of debt manageability problems and mental health outcomes. Specifically, adjusted odds ratios for anxiety ranged from 2.28 (‘some problems’) to 11.18 (‘very serious problems’), for depression ranged from 2.80 (‘some problems’) to 16.21 (‘cannot manage at all’), and for mental health help-seeking ranged from 1.69 (‘some problems’) to 3.18 (‘quite serious problems’, ‘very serious problems’). Conclusion This study highlights that debt manageability problems represent a robust predictor of depression, anxiety, and mental-health help seeking.