AbstractA regulatory sandbox is an emerging tool for addressing the challenges posed by the FinTech industry, but countries have embraced it to varying degrees. There is a need to systematically examine the question: Which factors explain the diverging trajectories in countries' decision to use (or not use) this instrument? This paper examines the adoption of regulatory sandboxes for FinTech in the Baltic states, where we can observe markedly divergent trajectories. Estonia has not exploited the possibilities of this instrument, while Lithuania and Latvia adopted a regulatory sandbox in 2018 and 2021, respectively. We analyze the political, legal, administrative, and economic factors affecting the adoption (or non‐adoption) of regulatory sandboxes for FinTech. We find that the decision to adopt a regulatory sandbox for FinTech is primarily influenced by the efforts of policy entrepreneurs, mechanisms of policy diffusion, and the policy actors' perceptions of legal constraints and available regulatory capacities.