Davis was fired on her face at a point blank range during a shooting incident in the school premises on December 13.
"Despite the best efforts of our physicians and nursing staff, and Claire's fighting spirit, her injuries were too severe and the most advanced medical treatments could not prevent this tragic loss of life," Littleton Adventist Hospital posted on the facility's official Facebook page, Reuters reported.
A number of prayer vigils were held for the wounded Davis in her community. She had been in a coma after the shooting.
18-year-old Karl Halverson Pierson went on a '80-second' shooting spree.
"The grace, laughter and light she brought to this world will not be extinguished by her death - to the contrary, it will only get stronger," the Davis family said in a statement.
The shooter, 18-year-old Karl Halverson Pierson went on a '80-second' shooting spree at Arapahoe High School in suburban Denver and injured two students and committed suicide in the library.
Pierson reportedly held a grudge against a specific male teacher who left the school premises after being alerted.
The other student suffered minor gunshot-related injuries and was released from the hospital hours later, authorities said.