Objective To investigate the causal effect of coronavirus disease 2019 (COVID-19) on idiopathic pulmonary fibrosis (IPF). Methods Genome-wide association studies (GWAS) data were sourced from the COVID-19 Host Genetics Initiative and published research. We employed: ① linkage disequilibrium score regression to estimate heritability of individual traits and genetic correlations between COVID-19 and IPF; ② multi-trait analysis of GWAS to identify genetic loci associated with COVID-19 and IPF; ③ Mendelian randomization (MR) to assess causal effect of COVID-19 on IPF; ④ colocalization analysis to identify shared causal variants. Results ① Three COVID-19 phenotypes showed significant positive genetic correlations with IPF (P<0.05); ② Multi-trait analysis of GWAS identified loci jointly associated with COVID-19 and IPF; ③ MR indicated that COVID-19 hospitalization may increase IPF risk (P=0.006); ④ Two causal variants were identified: rs12585036 (posterior probability>0.8, mapped to ATP11A) and rs12610495 (posterior probability>0.8, mapped to DPP9). Conclusions COVID-19 hospitalization may increase IPF risk through inflammatory pathways, providing new insights for managing COVID-19-related pulmonary diseases.