Locoweeds are perennial plants that inflict severe economic losses on livestock production globally. Oxytropis ochrocephala, a predominant locoweed species, is prevalent across the arid and semi-arid regions of China. Although prior studies have extensively characterized its neurotoxic effects in grazing livestock, the molecular mechanisms governing its stress tolerance remain poorly understood. The present study identified ABA-responsive element binding factor 1 (OoAREB1) as a stress-responsive transcription factor associated with O. ochrocephala. Subcellular localisation analysis confirmed its nuclear localisation, whereas yeast-based trans-activation assays demonstrated its capacity to activate reporter gene expression, thereby highlighting its role as a transcriptional regulator. Furthermore, the expression levels of OoAREB1 exhibited significant upregulation under multiple abiotic stresses in O. ochrocephala, with pronounced induction observed in response to drought and exogenous abscisic acid (ABA) treatment. Moreover, heterologous expression of OoAREB1 in Arabidopsis enhanced drought tolerance and increased ABA sensitivity. Although bioinformatics analyses predicted potential interactions between OoAREB1 and three sucrose nonfermenting 1 (SNF1)-related protein kinase 2 s (OoSnRK2) proteins, functional validation via yeast two-hybrid (Y2H), bimolecular fluorescence complementation (BiFC), and pull-down assays revealed specific interactions with OoSnRK2.1 and OoSnRK2.6. Additionally, both OoSnRK2.1/2.6 are capable of phosphorylating OoAREB1. Consequently, the transcript levels of OoSnRK2.1/2.6 were markedly elevated under drought stress and ABA treatment in O. ochrocephala. Therefore, this study demonstrated that OoAREB1 a key stress-responsive transcription factor isolated from O. ochrocephala functions as a master regulator of drought tolerance and ABA signalling in transgenic Arabidopsis.