The Nigeria international's short-term deal recently expired at The Den and Rangers boss Neil Warnock has tempted him back to west London.
"I just felt that with the injuries Fitz Hall has had this season that we were maybe one body light in the central defensive area," Warnock told the club's official website.
"We've got to look at every avenue for the last 19 games of what could be the most important period in the club's recent history.
"Dan wanted to come here and I wanted to get him, so it was a no-brainer in that respect. Dan knows the club inside-out and can't wait to get started."
Shittu made 182 appearances during a five-year spell at Loftus Road between 2001 and 2006.
Source: PA
Source: PA