Leeds have beaten competition from England and France to sign Parks, who has four caps for Wales, and he will be the club's eighth new signing of the close season.
Commenting on his signing Director of Rugby Phil Davies said, "I am delighted to have secured the services of Richard. He is a highly experienced, international quality player who will strengthen our squad considerably for the new season. He has the respect of many of our players having played against us for Pontypridd a couple of seasons ago. He gives us great options in our backrow, as an expert number 7 who can also play at 6 or 8.
"Richard is an intelligent footballer and will be a quality acquisition for the club. I know he is looking forward to joining up with us for pre-season," added Davies.
The Tykes have also confirmed that they will be making one more signing to complete their squad for the 2004-2005 season.
Members of the media are reminded that the Leeds Tykes Official Media Day is on Wednesday 11th August. If any members of the media are wishing to attend and have not already notified Phil Daly, please do so shortly so that numbers can be confirmed for lunch.