Abstract Background Evidence on health inequalities among young people is patchy compared to that among adults and younger children. This study examined the association between self-rated general health and a family’s socioeconomic position in young people. Methods We utilised 2001, 2011 and 2021 census microdata from England and Wales, and 2001 and 2011 data from Scotland. Descriptive methods were used to determine differences in general health status by sociodemographic variables, and logistic regression analysis to calculate the odds of reporting poor health according to the National Statistics Socio-economic Classification of the family reference person. Logistic regression models controlled for the effects of age, gender, household deprivation, and UK region. Results Compared to young people from households where the reference person belonged to the managerial or professional occupational group, all other groups, except those self-employed in 2001, had greater odds of reporting poor health. These differences were statistically significant (p < 0.001). The odds were highest among young people from households where the reference person had never worked or was long-term unemployed: 2.7 times in 2001, 3.1 times in 2011 and 3.6 times in 2021. The odds of reporting poor health increased with age and were greater among girls than among boys. Conclusions We observed a similar social gradient of self-reported poor health across the 2001, 2011 and 2021 census datasets; as disadvantage increased, the share of young people with fair or poor health increased.