Advanced non-malignant respiratory diseases are associated with significant patient morbidity, yet access to palliative care occurs late, if at all. To examine referral criteria for palliative care among patients with advanced non-malignant respiratory disease, with a view to developing a standardised set of referral criteria. Systematic review of all studies reporting on referral criteria to palliative care in advanced non-malignant respiratory disease, with a focus on chronic obstructive pulmonary disease and interstitial lung disease. A systematic review conducted and reported according to the Preferred Reporting Items for Systematic Reviews and Meta Analyses guideline was undertaken using electronic databases (Ovid, MEDLINE, Ovid Embase, and PubMed). Searches yielded 2052 unique titles, which were screened for eligibility resulting in 62 studies addressing referral criteria to palliative care in advanced non-malignant respiratory disease. Of 18 categories put forward for referral to palliative care, the most commonly discussed factors were hospital use (69% of papers), indicators of poor respiratory status (47%), physical and emotional symptoms (37%), functional decline (29%), need for advanced respiratory therapies (27%), and disease progression (26%). Clinicians consider referral to specialist palliative care for a wide range of disease- and needs-based criteria. Our findings highlight the need to standardise palliative care access by developing consensus referral criteria for patients with advanced non-malignant respiratory illnesses. Copyright ©The authors 2021. For reproduction rights and permissions contact permissions@ersnet.org.