The youngster was identified by West Yorkshire Police, after the memorial - which honours those who died in the disaster in May 1985 - was damaged last month.
Around 258 people were injured and 56 football fans were killed in the fire, which was caused by a discarded cigarette and happened at Bradford City AFC's ground Valley Parade in Bradford, West Yorks.
West Yorkshire Police today (Thurs) confirmed that the damage, which has now been fixed, was caused by a shopping trolley rolling into it and that a juvenile was identified through CCTV enquiries.
Sergeant Ross Longbottom said: "A full investigation has been carried out in relation the damage caused to the Bradford City memorial.
"It's been established that the damage was caused by a shopping trolley rolling into it, causing some minor damage which has now been repaired. "A juvenile has been identified through CCTV enquiries.
"Bradford City AFC, West Yorkshire Police and the education authority are working closely together to take appropriate action."
Following the damage to the memorial, a Bradford City spokesperson said the club was "appalled and disgusted."
They said: "To say this act is wholly unacceptable does not go far enough - it is utterly incomprehensible.
"This memorial is sacred to our club, our supporters, and the people of Bradford.
"It is a place of remembrance and reflection, honouring the 56 Bradford City and Lincoln City supporters who lost their lives in the Valley Parade Fire Disaster, and the hundreds more who were left with life-changing injuries.
"Since it was carefully installed in 2001, the memorial has been tended to daily by our staff, who clean and maintain it with the utmost care and respect.
"For someone to deface or damage it in any way is not only an attack on a physical tribute, but a disgraceful insult to the memory of those we lost and to the families and community still affected.
"While the damage has since been repaired, the pain this has caused cannot simply be undone.
"We stand together as a club and as a city in condemning this shameful act.
"Bradford City AFC will not tolerate such disrespect.
"We will always remember."
