Granite School District spokesman Ben Horsley says the gun went off while the woman was in a faculty restroom shortly before class started Thursday at Westbrook Elementary School, in the Salt Lake City suburb of Taylorsville. The teacher was rushed to the hospital.
Horsley says no other faculty or students witnessed the shooting, but some heard the gunshot.
He says the the bullet entered and exited the teacher's leg.
Horsley wouldn't release further details about the woman, but he says she was carrying the weapon legally with a concealed firearm permit.
Utah law allows anyone with a concealed carry permit to wear a gun in a public school.