It would help if you specify what sort of English you are using.
If you want to translate it into American English, I can't help.
If you want to translate it into British English, see here:
https://en.wikipedia.org/wiki/Ofsted
Quote:
"In September 2001, Her Majesty's Chief Inspector of Schools in England became responsible for registration and inspection of day care and childminding in England, and the position was renamed Her Majesty's Chief Inspector of Education, Children's Services and Skills."
So, if you're doing it in British English, it looks as though the title you need might be "[Her Majesty's] Chief Inspector of Education, Children's Services and Skills".
However, if your original text is in Spanish and it's talking about a Chilean school inspector, then obviously you can't use that title, as non-British citizens do not hold titles that make them answerable to her [British] Majesty.
Honestly, in everyday English, normal people would just say "a school inspector".
It depends on how formal your document is. If it's very formal, you'll have to use the full title. If not, just say "school inspector".