Welcome to the ACM International Conference on Supercomputing (ICS), June 26-28, 2019 in Phoenix, Arizona. This is the 33rd year of the conference. Over these 33 years, ICS has established itself as the premier technical forum for researchers in high-performance computing (HPC) to present their latest results and to discuss the state of the art. ICS 2019 continues the tradition of strictly peer-reviewed technical presentations, with selected tutorials and a workshop complementing the technical paper program. This year, ICS is being held in conjunction with the Federated Computing Research Conference (FCRC), which hosts many co-located conferences, offering attendees a rich set of programs and associated events. Among them are a set of inspiring plenary keynote talks that present diverse technical advances, viewpoints, and visions related to FCRC conference topics.