Bennett, 18, will remain at the Coral Windows Stadium until the start of January after penning his loan contract with the Bantams just hours before their Capital One Cup victory at Morecambe.
The talented forward was in the crowd at the Globe Arena (pictured) and he will officially join up with the rest of Parkinson's squad later this week ahead of City's match away to Walsall at the weekend.
Parkinson said: "Mason is someone we have tracked since the start of pre-season really. (Derby County manager) Steve McClaren and the rest of the staff at Derby have been great with us during that period. They have kept us informed all along about Mason's future.
"There was the possibility that he was going to go elsewhere as part of another deal but that fell through.
"To be fair to Derby, they came straight back onto us and said that the deal was back on.
"Mason was at the game tonight and I managed to have a good chat with him before the match.
"He'll be in training on Thursday morning and we can't wait to work with him."