Kian Hamer registered the maximum score of 162 on the Cattell III B paper, a test used by Mensa to assess IQ.
High-IQ society Mensa sent a letter to Hamer confirming he is among the top 1% of intelligent people in the world.
"I feel proud to have achieved such a good score and I'm really excited to be joining Mensa," said Kian.
"I always work my hardest in everything I do and I'm always up for a challenge."
Kian, of Coventry, West Midlands, took the test under supervised conditions at Woodlands Academy along with his Year 7 classmates in February 2016.
Even after receiving the letter from Mensa, Kian - who plays football for Coventry City's under-12s - is pretty set on not pursuing an academic career.
"I still want to be a professional footballer when I'm older though," he added.
"I just love playing football."
Kian's dad Rich Hamer, 43, who works as a firefighter, said he doesn't think his son realised what a good score it was.
"I want him to keep his feet on the ground," Hamer said. "He is clever but I'm not calling him a genius.
"A lot of people have joked that he's too clever to be a footballer.
"He's competitive but he's not big-headed and he's very down to earth. He's very matter-of-fact."
Hamer said he and his wife are both very proud and always knew Kian had it in him.
"He's always done incredibly well at school," he added. "He works really hard and always tries his best.
"We knew he was bright but never in our wildest dreams would we have thought about putting him in for a Mensa test. So, credit to the school.
"I am very proud of what he has achieved. I think he is pretty chuffed too."
The average adult has an IQ of 100, while a score above 140 is considered to be that of a "genius".
Mensa has 110,000 members worldwide, including 20,000 in the British Isles. Only 8% of members are under 16 and just 35% are female.
The Cattell III B test has 150 questions which assess comprehension through passages of texts.
The maximum possible score is 161 for adults, and 162 for under-18s.