The needs of family members of patients in the intensive care unit (ICU) with a severe traumatic brain injury (TBI) remain unmet. To date, no review has been performed to explore the experiences of relatives of adults who have been admitted to the ICU for treatment of a TBI. The aim of this scoping review is to explore and map the evidence of the experiences of family members when an adult relative is admitted to an ICU with a severe TBI. This review follows a combination of guidelines from Arksey and O’Malley and the Joanna Briggs Institute. Five electronic databases, Medline, Emcare, Embase, CINAHL, and PsycInfo were searched in February 2023, as were a number of grey literature sources. The population, concepts, and context framework were used to define the inclusion and exclusion criteria. From 4077 records, nine studies were retained, which represented seven discrete studies. The experiences of family members were thematically analyzed. The narrative synthesis of findings revealed three themes: communication with the clinical team, uncertainty, and involvement in care. These results offer richness and depth of understanding to clinicians regarding the experiences of families during this traumatic time. This review provides direction for targeted interventions aimed at supporting family members while in the ICU.