There were a total of 27 lost appeals for XP East last year, a Freedom of Information request revealed.
Hall Cross saw the second largest number of unsuccessful appeals, 24, with XP, the borough’s other free school, recording 20.
Other figures were Hungerhill 15, Outwood Academy Adwick six, Rossington All Saints five, Campsmount four, Hayfield School four, Trinity two, de Warenne one and Don Valley one.
The XP School Trust said in a statement: “XP and XP East are deliberately sized schools at 50 students per year. While we have immense pressure on us, we are 13 times oversubscribed for places at XP, an appeal will only be upheld if we have not followed the admissions process.
“Our admissions process, including appeals is undertaken independently by the Local Authority, and the fact no appeal has been upheld in the last five years, despite this pressure, is testimony to the integrity of this process.
“Our oversubscription criteria is random allocation.”
Simon Swain, principal at Hall Cross, said the upheld appeals reflected the number of applications the school received. He said sometimes pupils living in the catchment area for Hall Cross may apply unsuccessfully to other schools, and then come to the school as a third choice, potentially leading to appeals, which were heard by independent panels.
The most succesful appeals from parents fighting for places were at Outwood Academy, Adwick, with 13. Other schools to see successful appeals were de Warenne, six, Don Valley, five, Hungerhill School, five, Rossington All Saints, four, Hall Cross, three, Campsmount, three, Trinity, three, Ridgewood, two, Sir Thomas Wharton Academy, one.
A spokesman for Outwood Academy Adwick said it had become hugely popular, leading to significant annual oversubscription. Doncaster Council co-ordinates the admission process, allocates places and arranges its appeals.
He added: “We pride ourselves on being an inclusive setting and have a significantly higher proportion of disadvantaged students and those in Local Authority Care and it was the LA's decision to allocate these admissions to the academy.”