Ashley Banks, 14, who had been diagnosed with the behavioural disorder ADHD, was last seen alive by his parents playing on his games console.
But when his dad Shane went to tell him his favourite football team had won he found Ashley unconscious.
The teenager had only started at Horizon Community College in Barnsley last September and since his death friends have told the family he was being bullied.
Mr Banks, of Coronation Road, Hoyland, near Barnsley, said his son had never told him and his wife Donna that he had been bullied but there was no other reason for his death.
He said: “He was a cheeky and cheerful lad. He was a lovely lad. You just don’t dream of something like this happening to a young boy of 14.
“His family loved him and his friends loved him. We never thought he would have done something like this. It must have been on his mind to do something like he did.
“All I can put it down to is him being bullied and nothing has been done about it at school.”
Ashley moved from Kirk Balk School at Hoyland, Barnsley, and then on to Horizon because of behavioural problems.
The boy was found hanged last Saturday afternoon, and Mr Banks said he had noticed that his son’s mood had changed the evening before as the family had enjoyed a takeaway meal.
He said: “He was himself then he just went quiet now and again. We didn’t take much notice at the time but you could tell the difference.”
Paul Gallagher, co-principal at Horizon Community College, said Ashley had been upset when he left school on the Friday but there was no evidence to suggest he was being bullied.
He said: “The evidence from all the professionals who worked with him in and out of school suggested things were going well at school and there were signs of improvement.
“It is a sad day for the college and the community. Our thoughts and prayers go out to the family.”
A meeting is being arranged between school staff and the family to investigate the bullying claims.