She is the Camden Professor of Ancient History at the University of Oxford, a post established in 1622.
Arena was previously Professor of Ancient History at University College London.
Her work focuses on antiquarianism, Varro, ancient philosophy of language, and Roman constitutionalism.
The title of her doctoral thesis was Democratic Ideas and Political Practice in the Late Roman Republic.
Arena received a Consolidator Grant from the European Research Council (ERC) for her project, 'Ordering, Constructing, Empowering: Fragments of the Roman Republican Antiquarians' (2020–25).