Chait was serving as acting LAUSD superintendent after Alberto Carvalho was placed on leave in February amid an FBI investigation. Carvalho resigned on Sunday.
The LAUSD board voted unanimously in closed session to give Chait the full-time position.
Chait has led the district through labor negotiations, budget planning and the end of the school year.
Chait, who has been with the district for three decades, began his career with LAUSD as a kindergarten teacher, and went on to serve as an assistant principal, principal, Local District superintendent, chief of school operations and acting superintendent.
City News Service contributed to this report.