Philosophers and logicians have long inquired under which conditions two theories should count as theoretically equivalent, proposing a plethora of syntactic and model-theoretic criteria (e.g., definitional equivalence, bi-interpretability, categorial equivalence and so on). In recent years, this topic has gained renewed popularity thanks to various debates across philosophy. Among these, some notable examples are the equivalence between potentialist and actualist frameworks, and the lifting of type distinctions in higher-order metaphysics. This workshop aims to take stock of these developments, clarify the landscape of competing notions of theoretical equivalence, and explore their implications for contemporary philosophy of science and mathematics. The event will bring together the team of C-FORS members actively working on the topic and three external leading experts in the field, whose contributions have significantly shaped the debate over the past decade.