The incident took place at Dera Ismail Khan district near Peshawar in the province.
As many as 19 people belonging to four different families were on board the ill-fated tractor when it met with the accident, police said.
The driver of the vehicle was said to have lost control over the vehicle while crossing Awan drain which resulted in the tractor felling into the canal.
Police said that seven children and two women died on the spot while cops managed to rescue others.
Further investigations were underway.