This study investigates the diet of an eleventh century CE parish community located in northwestern Germany. We assessed the isotopic compositions of human (n = 24) and faunal (n = 17) bone collagen (δ13Ccol, δ15Ncol) and human structural carbonate (δ13Csc) using skeletal material recovered from the Dalheim cemetery. Traditional interpretation of the isotopic data indicates that Dalheimresidents likely relied on a C3 plant-based diet and consumed some terrestrial animal products without evidence of marine resource input in the diet. Bivariate and multivariate models used as an additional means to assess diet indicate minor consumption of C4 plant foods in this community. The multivariate-isotope model identified regional similarities and differences in C4 plant/marine food consumption and in dietary protein sources by comparing data from Dalheim with those of other medieval sites from the published literature.We did not observe sex differences in this population but differences in δ15Ncol suggest that juveniles consumed the lowest trophic level protein.