To evaluate the genetic relationship between hypertension and COVID-19 and explore the molecular pathways linking hypertension to COVID-19. We performed genetic correlation and Mendelian randomization (MR) analyses to assess potential associations between hypertension and hospitalized COVID-19. We compared genome-wide association signals to reveal shared genetic variation between hypertension and hospitalized COVID-19. Moreover, hypertension-driven molecular pathways were constructed based on large-scale literature data to understand the influence of hypertension on COVID-19 at the molecular level. Hypertension has a positive genetic correlation with COVID-19 (r g = 0.19). The MR analyses indicate that genetic liability to hypertension confers a causal effect on hospitalized COVID-19 (odds ratio [OR]: 1.05, confidence interval [CI]: 1.00-1.09, p = 0.030). Hypertension and hospitalized COVID-19 have three overlapping loci and share eight protein-coding risk genes, including ABO, CSF2, FUT2, IZUMO1, MAMSTR, NPNT, RASIP1, and WNT3. Molecular pathway analysis suggests that hypertension may promote the development of COVID-19 through the induction of inflammatory pathways. Our study suggests that genetically determined hypertension may increase the risk for severe COVID-19. The shared genetic variation and the connecting molecular pathways may underline causal links between hypertension and COVID-19.