Lung cancer is the most common cause of death from cancer worldwide, and its incidence is increasing in East Asian and Western countries. To identify genetic factors that modify the risk of lung adenocarcinoma, we conducted a genome-wide association study in a Japanese cohort, with replication in two independent studies in Japanese and Korean individuals, in a total of 2,098 lung adenocarcinoma cases and 11,048 controls. The combined analyses identified two susceptibility loci for lung adenocarcinoma: TERT (rs2736100, combined P = 2.91 × 10⁻¹¹), odds ratio (OR) = 1.27) and TP63 (rs10937405, combined P = 7.26 × 10⁻¹²), OR = 1.31). Fine mapping of the region containing TP63 showed that a SNP (rs4488809) in intron 1 of TP63 showed the most significant association. Our results suggest that genetic variation in TP63 may influence susceptibility to lung adenocarcinoma in East Asian populations.