Manager Walter Smith will be hoping that the Frenchman will be able to fill in on the left wing after the departure of Charlie Adam and the below par performances from DaMarcus Beasley.
“I am absolutely delighted to be joining Rangers, a massive club with a great history,” Rothen told the club’s official website.
“It has been a very busy day, but I have been very impressed with everything and now look forward to a new chapter in my life.
“I did have other offers from Schalke and Blackburn, but I just felt that Rangers offered something different.
“Playing in the Champions League is, of course, great for the club but there is also a big chance to win trophies in Scotland. This is important for any footballer.”
