Quantified Boolean formulas (QBF) are an extension of propositional logic which allows for explicit quantification over propositional variables. The decision problem of QBF is PSPACE-complete, compared to the NP-completeness of the decision problem of propositional logic (SAT). Many problems from application domains such as model checking, formal verification or synthesis are PSPACE-complete, and hence could be encoded in QBF in a natural way. Considerable progress has been made in QBF solving throughout the past years. However, in contrast to SAT, QBF is not yet widely applied to practical problems in academic or industrial settings. For example, the extraction and validation of models of (un)satisfiability of QBFs has turned out to be challenging, given that state-of-the-art solvers implement different solving paradigms. The goal of the International Workshop on Quantified Boolean Formulas (QBF Workshop) is to bring together researchers working on theoretical and practical aspects of QBF solving. In addition to that, it addresses (potential) users of QBF in order to reflect on the state-of-the-art and to consolidate on immediate and long-term research challenges. The workshop also welcomes work on reasoning with quantifiers in related problems, such as dependency QBF (DQBF), quantified constraint satisfaction problems (QCSP), and satisfiability modulo theories (SMT) with quantifiers.