This book constitutes the refereed proceedings of the 27th Brazilian Symposium on Formal Methods: Foundations and Applications, SBMF 2024, held in Vitória, Brazil, during December 4-6, 2024. The 8 full papers and 4 short papers included in this book were carefully reviewed and selected from 18 submissions. They were organized in topical sections as follows: Formal Analysis and Verification in Temporal and Symbolic Systems; Formal Semantics and Verification of UML Models; Formal Verification and Proof Techniques in Algorithms and Logics; and Formal Methods for Security and Privacy.