In California?

From Bearing Arms:

After a unanimous vote by the school board, Kingsburg Joint Union High School District teachers will be allowed to concealed carry on campus.

On Monday, with little opposition at the meeting, the school board approved the measure citing with the school, which houses about 1,200 students, and it’s lack of a surrounding fence, no police officer on campus, and their open campus which allows students to leave school grounds at lunchtime. Staff with valid concealed carry permits are welcome to fill out an application to carry in school.
Chosen employees will still need to complete training, which will be approved by Superintendent Randy Morris, and their discipline record and school conduct will be taken into consideration.