During the Iron Age, north-eastern Iberian communities relied on crop cultivation and animal husbandry for their subsistence. The latter was mainly focused on caprine, with sheep being prominent due to their suitability to the Mediterranean climate, orography, and environment. Despite the pivotal role of sheep in livestock husbandry, information on Iberian communities’ feeding strategies for this species is limited. To address this lacuna, this study investigates the livestock feeding habits at four Catalan sites dating back to the 3rd century BC: Mas Castellar de Pontós, Tossal de Baltarga, Sant Esteve d’Olius, and Turó de la Rovira. Bulk carbon and nitrogen isotope analyses (δ13C and δ15N) of bone collagen and sequential carbon and oxygen analyses (δ13C and δ18O) of dental enamel were performed on 74 remains (43 bones, 31 teeth) from 51 sheep. Additionally, 153 bone remains from other domestic and wild species from the four sites were analysed. Our results revealed the complex and adaptive livestock feeding strategies of Iron Age Iberian populations. Sheep exhibited minimal diet variations, mainly consuming C3 plants across the four sites. Nevertheless, their feeding habits changed seasonally depending on pasture availability and settlement requirements. The other main domestic species were subject to individualised and variable feeding strategies within the same settlement. This diversified feeding management unveiled the complex and adaptive nature of the husbandry practices employed by Iron Age Iberian communities. Finally, the extensive number of remains analysed provides the first data on livestock feeding strategies for the Middle/Late Iron Age in the north-eastern Iberian Peninsula.