The BOS Webinar Series is a new initiative of the Bilevel Optimization Society (BOS), which is part of the Mathematical Optimization Society (MOS). This online seminar series is open to anyone interested in bilevel optimization and provides a platform to present new ideas, share results, and discuss open questions in theoretical, computational, and applied bilevel optimization. Each season, the series features talks by internationally recognized experts alongside emerging researchers, highlighting recent and impactful advances in bilevel optimization.