Since his debut for the Bulls, he has been a mainstay in one of the most dominant packs in world club rugby for close to a decade.
Testament to his form and durabilty, the 29-year-old has made 99 consecutive Super Rugby appearances for the Bulls, amassing a total of 113 Super Rugby caps.
Wannenburg's introduction to Super Rugby immediately brought him to the attention of the national selectors, and he made his Springbok Test debut against France in November 2002. He has 20 Springbok caps to date.
Commenting on his move to Ulster, he said: "It was not an easy decision after almost a decade with the team and the Bulls family.
"But it is also a good time to move on. The Heineken Cup will be a new challenge and I am looking forward to that.
"I have heard many good things about Ulster and I am keen to contribute to them, as I still have a lot to offer."
The capture of Wannenburg completes Ulster's impressive quota of non-irish qualified players for the coming season.
Ulster Rugby's Director of Rugby Operations, David Humphreys, said: "Ulster Rugby is looking forward to welcoming Pedrie, another world class South African forward, to Belfast, adding the final piece to the Ulster squad for the 2010/11 season.
"A lot has been spoken about the potential of this current Ulster squad and we are committed to signing the highest quality players who, like Pedrie, through their winning mentality, have the ability to improve our performances on the pitch and take Ulster Rugby back to the highest level.
" I have no doubt Pedrie will be an enormous asset to Ulster. Ulster Rugby would like to thank the Blue Bulls for affording Pedrie the opportunity to continue his rugby career with Ulster."
In light of this announcement, Ulster can confirm that Xavier Rush will not be joining the province next season.
Rush, who had signed a two-year deal with Ulster in February, recently requested that, for personal reasons, he did not wish to leave Cardiff.
Ulster have agreed to release Rush from his contract, allowing him to recommit to the Cardiff Blues.