This is Camerons first ever loan spell away from Villa Park after playing in all 23 reserve games last season.
Cameron told Millers player: "I have been playing for Aston Villa under 21s and was made aware a few clubs had expressed an interest in signing me.
“My agent got a call from Rotherham United and then from Steve Evans and it went from there.
“The stadium is fantastic; I spoke to the manager and the assistant and was impressed with what they had to say, so I am just really excited about getting started.
“I am a wide man by trade but I can play left-back or on either flank,” added Courtney. “I like to stay wide and get crosses into the box and provide for the strikers, and hopefully I can do that.”
Courtney is with the Millers until 5th January and can play at left back aswell as the left wing. MillersMAD wish him every success.