The World Green Chemistry & Environmental Engineering Summit (WGCEES-2026) will be held from June 25–27, 2026, in Barcelona, Spain, bringing together leading researchers, academicians, industry experts, policymakers, and young scientists from around the world. The summit aims to provide a global platform to discuss recent advancements, innovative technologies, and sustainable solutions in green chemistry, environmental engineering, environmental sustainability, climate change mitigation, and circular economy practices. WGCEES-2026 will feature keynote lectures, invited talks, technical sessions, poster presentations, and networking opportunities, fostering interdisciplinary collaboration and knowledge exchange to address pressing environmental challenges and promote sustainable development.