The school was presented with the award by Laura Kearney, from Osiris Educational.
Visible Learning plus is a pioneering programme which identifies what makes the biggest impact on pupils’ learning.
Since starting the programme 18 months ago, St Hugh’s has seen remarkable results in pupils’ progress and motivated staff.
St Hugh’s Headmaster, Chris Ward, said: “This a tremendous achievement as it is an international accreditation and we are the first Prep school in the UK to be awarded Level 2.
“My thanks go to all the staff and pupils for their hard work and dedication in embedding the Visible Learning principles across St Hugh’s.”