AbstractBackgroundEvidence on the impacts of parental and early life socio‐economic position (SEP) on health outcomes in adulthood remains mixed. This systematic review and meta‐analysis investigated the association between low parental SEP and adult cardiometabolic and inflammatory markers in individuals aged 18 years and older.MethodsA systematic search across five databases (EMBASE, Ovid MEDLINE, Cinahl, Global Health and Maternity and Infant Care until January 01, 2022) identified observational studies linking parental SEP with adult cardiometabolic and inflammatory markers. Pooled Standardized Mean Differences (SMD) were estimated using random‐effects models. Risk of bias, heterogeneity and publication bias were assessed using the Cochrane tool, subgroup analysis and Egger's test, respectively.ResultsThe review included 38 studies (12 in meta‐analysis, n = 388,674). Findings showed that lower parental SEP was significantly associated with elevated blood pressure (SMD = .30 mmHg; 95% CI: .10, .50; I2 94%; n = 5), increased adiposity (SMD = .56; 95% CI: .05, 1.07: I2 98%; n = 6), higher C‐reactive protein levels (SMD = 1.45 mg/dL; 95% CI: .06, 2.85; I2 80%; n = 9), elevated IL‐6 (SMD = 2.12 pg./mL; 95% CI: −.72, 4.97; I2 100%; n = 4) and higher allostatic load (SMD = .85; 95% CI: .30, 1.40; I2 99%; n = 4). No consistent associations were found for glucose or lipid markers. Gender‐specific variations were observed.ConclusionsLow parental socio‐economic position negatively impacts adult offspring health, manifesting as higher blood pressure, elevated C‐reactive protein, increased interleukin‐6, greater adiposity and higher allostatic load. Future research should prioritise three critical areas: mechanistic specificity, intersectional pathways and life‐course timing and critical period detection.