Lucian George trawled through the 32 volumes of the Encyclopaedia Britannica and found inaccuracies in the entries on Poland and the wildlife of eastern Europe.
The first mistake was a reference to the small town of Chochim - which the encyclopaedia placed in Moldova, according to newspaper reports.
Lucian, a pupil at the independent Highgate junior school in north London, said this was "wrong". "Chochim is in Ukraine."
He also found that the encyclopaedia had wrongly stated that the European bison can only be found in the Bialowieza forest in Poland.
Lucian told the Times: "The European bison also inhabits the southern mountains of Poland, Russia, Lithuania, Belarus, Ukraine, eastern Slovakia and the Romanian Carpathians."
The youngster acquired his knowledge because his mother is Polish and he has always been fascinated by the history of the country. He spends a month every year on a farm in Yamy, south west Poland.
Lucian's father Gabriel, said he was just a "normal kid". He told the Daily Mail: "He is intelligent and is surrounded by other intelligent children but he enjoys his Simpsons on TV just like anyone else."
Anita Wolff, the senior editor of the 15th edition of Encyclopaedia Britannica, thanked Lucian for pointing out "several errors and misleading statements". The section on Poland is now being rewritten.
Lucian said that despite the mistakes, he still thought the encyclopaedia was the best reference book he knew.
Nice to see the professionals outsmarted by a schoolboy
I'm famous for it around here & people have been known to avoid me in the street. I even confuse myself at times. 
