Parry said: "Andy is a classy player who has great vision, can score goals and create chances for others.
"His ability at set plays will add to what we've already got at the club and I'm really pleased to have him in the squad.
"I'm delighted with the contribution of our fans whose efforts have enabled us to bring a player of such high calibre to the club. I'd like to thank Leeds manager Simon Grayson for allowing Andy to join us on loan."
The 30-year-old opted to sign for Leeds in the summer of 2008 after playing a starring role for Swansea in their promotion to the Championship and was a regular for the Yorkshire club last season. He has scored seven goals in a total of 50 appearances, but has only featured on nine occasions this time around.