Aim: This study retrospectively analyses the impact of the 1st year of the COVID-19 pandemic on route of presentation and staging in lung cancer compared to the 2years before and after implementation of the Leicester Optimal Lung Cancer Pathway (LOLCP) in Leicester, United Kingdom. Method: Electronic databases and hospital records were used to identify all patients diagnosed with lung cancer in 2018 (pre-LOLCP), 2019 (post-LOLCP), and March 2020-2021 (post-COVID-19 lockdown). Information regarding patient characteristics, performance status, stage, and route of diagnosis was documented and analysed. Emergency presentation was defined as diagnosis of new lung cancer being made after unscheduled attendance to urgent or emergency care facility. Results: Following implementation of the LOLCP pathway, there was a significant decrease in emergency presentations from 26.8 to 19.6% (p = 0.002) with a stage shift from 33.9% early stage disease to 40.3%. These improved outcomes were annulled during the COVID-19 pandemic, with emergency presentations increasing to 38.9% (p < 0.001) and a reduction in early-stage lung cancer diagnoses to 31.5%. There was a 61% decline in 2week wait referrals but no significant decline in the LOLCP direct-to-CT referrals. Conclusion: We have demonstrated a significant increase in late-stage lung cancer diagnoses and emergency presentations during the first year of the COVID-19 pandemic. The causes for these changes are likely to be multifactorial. The long-term effect on lung cancer mortality remains to be seen and is an important focus of future study.