The summer school on XR invites CHI participants to Copenhagen, Denmark, for three days 2-4th May. The participants will learn about a wide range of topics across Human–Computer Interaction with Extended Reality, including XR prototyping, eye-tracking, haptics and perception. The six learning sessions in the first two days consist of introductory lectures, brainstorming, and hands-on hackathon activities, as well as an engaging and fun social program. The grand finale of the summer school will be a larger one-day symposium on XR, where the summer school participants will be joined by other XR researchers to hear featured talks from leading international XR researchers, including Mar Gonzalez-Franco, and a panel discussion about the grand challenges on XR and health by local XR industry leaders. The summer school participants will present their own ideas in a poster and demo session at the symposium and participate in a symposium dinner. This school is ideal for PhD students who are interested in learning about and actively participating in designing the future of XR.