Background: Frailty is a syndrome characterised by increased vulnerability to negative outcomes. Interstitial lung disease (ILD), asthma, and pleural disease are leading causes of morbidity and mortality. We aimed to investigate the prevalence and impact of frailty in adult patients with these diseases. Methods: We conducted a systematic review and meta-analysis, searching PubMed, Web of Science, The Cochrane Library, and EMBASE for studies reporting on frailty in ILD, asthma, and pleural disease. MeSH terms including interstitial lung disease, Idiopathic Pulmonary Fibrosis, Non-specific Interstitial Pneumonia, Chronic Hypersensitivity Pneumonitis, systemic sclerosis-associated ILD, connective tissue disease-associated ILD, and frailty were used as key words. The primary outcome was prevalence of frailty. Where enough contextually homogeneous studies were included, a pooled random-effects meta-analysis was performed with mortality and hospitalisation as the outcomes. Results: The review found three studies relating to frailty in asthma. No studies relating to pleural disease and frailty were identified. The median prevalence in asthma was 9.5% (IQR, 7.8–11.3). Six relevant studies incorporating 1471 ILD patients (age 68.3 ± SD2.38; 50% male) were identified, which were either cohort or cross-sectional design rated either good or fair. The median prevalence of frailty was 48% (IQR, 25–50). There was a positive association between frail ILD patients and increased risk of long-term mortality (pooled OR, 2.33 95%CI 1.31–4.15, I2 9%). One study reported a hospitalization rate of HR = 1.97(1.32–3.06) within 6 months in frail ILD patients. Conclusions: Frailty is very common and associated with increased mortality in patients with ILD. There are still minimal data regarding the prevalence of frailty and its influence on the risk in this population.