Naima Jewish Preparatory School has been rated "outstanding" by the Independent Schools Inspectorate (ISI) after an inspection in June.
ISI, which regulates independent schools in the UK, found that the west-London school's setting "makes outstanding provision in meeting the needs of the range of children who attend".
The report added: "It successfully achieves its aim of providing an excellent secular education together with a strong Jewish grounding."
A spokesperson for the school - whose principal is Rabbi Abraham Levy, the emeritus spiritual head of the Spanish and Portuguese Jews' Congregation - said that teachers at the school were "extremely proud" of the result.
"It serves as a tribute to the continued hard work put in by our members of staff," the spokesperson said.
