The order comes amid rising concern over the safety of students in schools following the brutal killing of a seven- year-old boy in a Gurgaon school and the alleged rape of a five-year-old girl by a school peon in Delhi.
No outsider or unidentified person will be allowed on the school premises for "stay purpose" during the daytime or at night, a communication sent to schools read.
School authorities have been asked to cross-check that "no illegal occupancy is taking place in their school/ office premises".
Schools have also been asked to conduct police verification of all the outsourced staff, including security guards, sanitation workers and data entry operators.
During a midnight raid led by Deputy Chief Minister Manish Sisodia at an East Delhi MCD school, it was found the school guard had been renting out classrooms at night.