The 27-year old has joined the Glasgow outfit, who will compete in Scotland's Third Division, on a four-year deal as a free agent after his Killie deal expired at the end of last season.
"I'm over the moon to be here. First and foremost, I wanted to sign for Rangers. No matter what league they are in, it's a massive club," Shiels said.
"I can't wait to get started. I'm delighted to be here, it's one of the biggest clubs in the world."