Introduction and aim Low socioeconomic position (SEP) has been shown to be strongly associated with impaired lung cancer survival. Barriers related to receiving recommended treatment among patients with lung cancer with low SEP may include adverse health behaviour and limited physical and psychosocial resources influencing the ability to react on high-risk symptoms and to navigate the healthcare system. To address the underlying factors that drive both decisions of treatment, adherence to treatment and follow-up in vulnerable patients with lung cancer, we developed the Navigate intervention. The aim of this randomised controlled trial is to investigate the effect of the intervention on survival (primary outcome), lung cancer treatment adherence, health-related quality of life and other psychosocial outcomes as well as health costs and process evaluation (secondary outcomes) in a study population of vulnerable patients with lung cancer. Methods and analysis This two-armed multicentre randomised trial will recruit patients from five lung cancer clinics in Denmark identified as vulnerable according to a screening instrument with nine clinical and patient-reported vulnerability criteria developed for the study. We will enrol 518 vulnerable patients >18 years old diagnosed with non-small cell lung cancer at all stages with a performance status <2. Participants will be randomly allocated to either standard treatment and intervention or standard treatment alone. The Navigate intervention is based on principles from motivational interviewing and includes three components of nurse navigation, systematic monitoring of patient-reported outcomes (PROs) and physical exercise in a person-centred delivery model. Data will be collected at baseline and 3, 6, 12 months after randomisation using questionnaires, clinical data and physical function tests. Ethics and dissemination Ethics Committee, Region Zealand (SJ-884/EMN-2020-37380) and the Data Protection Agency in Region Zealand (REG-080-2021) approved the trial. Participants will provide written informed consent. Results will be reported in peer-reviewed journals. Trial registration number NCT05053997.