The REFSQ working conference is the leading European conference series on requirements engineering. It is the goal of REFSQ to foster the creation of a strong European RE community across industry and academia. Since 1994, Requirements Engineering continued to be a dominant factor influencing the quality of software, systems and services. REFSQ seeks contributions which report on novel ideas and techniques that enhance the quality of RE’s products and processes, as well as reflections on current research. REFSQ has a long tradition of being a highly structured and interactive forum. REFSQ 2021 is scheduled to be held physically in Essen on April 12-15, 2021. Authors affected by travel restrictions will be given the opportunity to present their work virtually.