Moore has yet to fully establish himself at Villa Park and featured only sporadically last season in The Premiership.
The 20-year-old did score against Blackburn Rovers but Villa boss David O'Leary feels Moore will benefit from a spell away from the club.
Millwall are capable of offering the young hot-shot regular playing time and the deal should be completed early next week.
The Birmingham-born forward is looking forward to playing for last season's FA Cup finalists and feels The Lions are the ideal club to join.
"I spoke to David O'Leary and he told me that he was happy for me to go out on loan and when Millwall came in I was pleased to come here," Moore told Millwall's official website.
"I want to play regular first team football and I'm looking to do well at Millwall.
"I saw the way Millwall played last year and I thought that this is a team which will suit my style."
Though Moore will officially move next week, he will feature in Millwall's pre-season friendly against Wycombe Wanderers on Saturday.
Meanwhile, Villa defender Liam Ridgewell has undergone surgery on the knee injury he suffered against Orgryte in a friendly.
Ridgewell will be out of action for three months after X-rays confirmed he had suffered knee ligament and cartilage damage.
