Proboscideans, and elephants in particular, played a key role in Pleistocene mammal communities in Europe. The British Pleistocene fossil record provides a unique opportunity to study changes in proboscidean feeding ecology associated with environmental proxy data such as pollen records and the presence of competitors. Here we utilize a recently introduced dietary analysis method, mesowear angle analysis, for studying relationships between dietary variation in proboscideans, changes in available vegetation and the presence of sympatric proboscidean species. The method is based on recording the relief of worn molar surfaces as angle measurements, which reflect attrition‐ vs. abrasion‐dominated feeding and serve as a proxy for grazing vs. browsing diets. By comparison with pollen records, we show that blunt mesowear angles specifically reflect grass eating rather than open‐ground feeding in general. We further find that all British Pleistocene proboscidean species were relatively flexible feeders able to shift their dietary preference according to local vegetation composition. Nonetheless, when more than one proboscidean species occurred in the same environment, they always show significantly different mean mesowear signal, suggesting dietary niche separation.