UFC on ESPN 27: Sandhagen vs. Dillashaw was a mixed martial arts event produced by the Ultimate Fighting Championship that took place on July 24, 2021, at the UFC Apex facility in Enterprise, Nevada, part of the Las Vegas Metropolitan Area, United States. A bantamweight bout between former two-time UFC Bantamweight Champion T.J. Dillashaw and Cory Sandhagen served as the event headliner. It was Dillashaw's first fight since his two-year suspension due to testing positive for recombinant human erythropoietin (EPO), which resulted in his title vacancy.