The 17-year-old was arrested on Tuesday, January 29 on suspicion of dealing cannabis to students near to B&M, Church View.
He admitted the offence.
PC Andrew Felters, of the Doncaster Central neighbourhood policing team, said: “The male in question admitted the offence and will be appropriately dealt with.
“Please be aware, if your children attend college of the dangers surrounding drugs and the consequences later in life if they are caught with it on them. A caution or charge could seriously damage any future job prospects and travel to other countries.”