Quantum science and technology promise to revolutionize information processing, communication, and sensing, thereby promoting the second quantum revolution and advancing quantum mechanics in the industrial sector. The development of quantum technologies has been made possible by several scientific disciplines, including quantum optics, nanoscience, condensed matter physics, and computer science. The ninth version of the workshop, QUOST IX, will generate a suitable environment for discussing recent developments in quantum technologies. QUOST IX will be an in-person conference in the Campus Casa Central of the Universidad Técnica Federico Santa María.