The COVID-19 pandemic disrupted healthcare systems globally, significantly impacting the continuum of care for diseases such as lung cancer (LC), which is the deadliest cancer worldwide. Preliminary evidence suggests shifts toward more advanced LC stages at diagnosis during the pandemic, with potential changes in treatment and survival outcomes. This study provides a comprehensive nationwide analysis of these trends.This retrospective cohort study analyzes data from the November 2022 update of the Surveillance, Epidemiology, and End Results (SEER) database, focusing on LC patients diagnosed between 2018 and 2020. The analysis compares diagnostic stages, treatment delays, and survival outcomes before and during the pandemic, employing logistic regression, Cox proportional hazards, and Fine-Gray competing risks regression models.The study included 106,226 LC patients, with findings indicating more advanced stages at diagnosis and shorter treatment delays in 2020 compared to the previous two years. The overall incidence of LC decreased significantly in 2020, with variations across different demographics and histologic subtypes. Despite these changes, no significant differences were observed in overall survival (OS) or lung cancer-specific survival (LC-SS) between the groups. The COVID-19 pandemic has led to later-stage LC diagnoses and somewhat quicker initiation of treatment, although it did not significantly impact short-term survival outcomes. These findings underscore the resilience of LC management under pandemic constraints and highlight the need for ongoing vigilance to mitigate long-term impacts on patient care and outcomes.