The former Scotland international striker has penned a one-year deal on his return to Ibrox after a spell with Vancouver Whitecaps came to a premature end in July.
Miller spent just over a year at the fallen Glasgow giants, but struggled to become a first-team regular and went on to join Wolves, Derby County and Rangers' arch-rivals Celtic.
He won a hat-trick of Scottish Premier League titles after resigning with the club in June 2008 and a third move back to Rangers has long been mooted, with the 34-year-old delighted to finally complete the formalities.
Miller told the Championship club's official website: "It's obviously been a long time coming and it's no secret I've been trying to come back for probably a few transfer windows now.
"So to get back now and play a part in what will be a tough Championship league next year is great.
"That's an understatement to be honest and I've not had the smile off my face since I knew it was going to happen.
"It was something that, after spending a few years across in Canada and with the little one going to school as well in the next few months, was always on the radar to come back to Britain at the end of my time in Vancouver.
"For me the first choice was Rangers and I'm absolutely over the moon that it's managed to go that way."