Aim: The study aim was to co-design new pediatric procedure room prototypes with children, caregivers, and healthcare providers (HCPs). Background: Medical procedures can cause pain and anxiety for children and their families. If spaces are not designed for patients’ needs, procedures may take longer, require sedation, and result in an inferior care experience. Involving HCPs in co-designing optimal spaces can result in more efficient and safer environments. co-designing spaces with patients and their families can inform psychologically safer and less traumatic environments. Methods: We followed human-centered design methodology. Data were collected via semi-structured interviews, field observations, and two multidisciplinary design workshops with patients, caregivers, and HCPs. Themes from the data were extracted using a content analysis and used to make evidence-informed recommendations for design features. Results: The study took place from October 2021 to February 2022. Patients, families, and HCPs reported similar needs: (1) control over the environment, including the ability to adjust lighting, temperature, and sound; (2) space that supports patient privacy; (3) the use of evidence-based pain reduction and distraction methods; (4) attention to the sensory environment, including visual (light, color), tactile (textures of furniture and equipment), auditory, and olfactory stimuli; (5) human factors organization of the space and equipment; (6) accessible and equitable spatial design; and (7) the significance of the journey leading up to and after the procedure. Conclusions: It is feasible to co-design procedure rooms that support evidence-based psychological, physical, and pharmacological interventions that are known to minimize pain for children.