Historical evidence suggests that social status played a major role in all aspects of society in eighteenth–nineteenth century England. We present an insight into how socioeconomic status affected the dietary habits of two post-medieval urban populations from Greater Manchester, northwest England. Stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotope ratios were measured in humans from Cross Street Unitarian Chapel (middle class: n = 90) in Manchester city centre and Chapel Street, Hazel Grove (lower status with few middle-class individuals: n = 34). A large sample of 111 faunal remains from Cross Street (n = 37) and Norton Priory, Cheshire (n = 74), provide an animal baseline, dramatically expanding the post-medieval animal isotopic dataset for England. Sheep from Norton Priory show high δ¹⁵N isotope values indicative of saltmarsh grazing. Results for human populations revealed a mixed diet of plant and animal protein from C₃ terrestrial environments with some potential contribution of aquatic protein. Significant differences revealed between the two populations indicate unequal access to food by status. Intra-population variation at Hazel Grove suggests dietary distinctions by age and sex. Non-adults consumed diets poor in high trophic level protein, whereas adult males consumed greater amounts of animal products. Conversely, the data suggests that at the wealthier Cross Street, there was greater access to high trophic level protein by all. Comparisons between the Manchester populations and those from similar socioeconomic classes from the Midlands and southern England, including London, reveal a bioarchaeological picture of dietary diversity and differential access to resources which impact significantly on well-being during this tumultuous period of industrial England.