Within enlargement policy, a distinctive feature is pre-accession assistance funding. Although European funds originated at the very beginning of the European integration process, each enlargement round has prompted adaptations in European Union (EU) funding, whose history is closely intertwined with enlargement policy and new EU memberships. The Palgrave Handbook of European Union Enlargement and Pre-Accession Assistance explores the design, evolution, implementation, and outcomes of pre-accession assistance across multiple enlargement rounds and candidate countries, and offers a unique thematic focus on how pre-accession assistance functioned across time, countries, and political settings. This pioneering handbook is the first publication to compare past and present recipients of pre-accession assistance, highlighting both similarities and differences in each case study and enabling cross-country comparisons. It critically analyzes how pre-accession assistance instruments both reflected and shaped the broader EU policy architecture and influenced candidate countries’ political and developmental trajectories on their path to EU membership.