Hall, who helped the Dons win promotion to the Sky Bet Championship last season following his arrival in Milton Keynes in March, is back on a season-long deal for the 2015-16 campaign.
The 21-year-old enjoyed his time with Karl Robinson’s team last season and jumped at the chance to return.
“It was an easy decision,” said Hall, who also spent time on loan at stadium:mk during the 2011-12 campaign.
“I’m just happy that I’m back here and I can’t wait to get going with the lads again.
“Coming here last season revitalised my whole career, having the freedom to go and play. I got on really well with the gaffer and the staff and the lads were great too.
“This was an opportunity I couldn’t turn down – at home, playing for a great club like MK Dons.”
Dons boss Robinson added: “It was clear for all to see at the back end of last season what Hally is capable of and he’s shown tremendous hunger and desire to want to come here for a third spell – we are more than happy to have him back too.
“He’s an exciting young English talent and he’ll add another dimension to our attack.”