Yavneh College in Hertfordshire is to offer a bulge class next September, enabling it to take an extra 30 students into year 7.
The school said it was responding to a large demand for places.
Applications for entry into state secondary schools next year had to be submitted by the end of last month. But most parents will not find where their children will go until March at the earliest.
Spencer Lewis, the college’s executive headteacher, said, “We are pleased to be able to help as many families as possible by providing extra school places for September 2025 giving them access to the first-class secular and Jewish education of which we are so proud at the Yavneh schools.”