Wirripang Public School at Gateshead is the state's most crowded school at 220% capacity according to figures released by the Department of Education.
The documents containing the figures were obtained under Freedom of Information laws and also reveal more than a third of NSW schools are at 100% capacity or more.
Charlestown MP Jodie Harrison says the results are a big reflection of the governments inability to plan, contrary to its commitment to public education.
"It [Wirripang Public School] opened in 2013 under this Liberal government. Now three years later, we've got overcrowding of 220 per cent. Wirripang Public School is over enrolled and what that means is this Liberal government is failing to plan for population growth let alone existing population."
The other five schools in the Hunter which are at more then 100% capacity include Islington Public School, Jesmond Public School, Grahamstown Public School, The Junction Public School and Maitland Grossmann High School.
