Edinburgh Rugby head coach Michael Bradley said: "We're delighted to have signed WP Nel for the next three seasons. He's a player of the calibre, experience and expertise that we seek to attract to the club and to serve our ambitions to put Edinburgh Rugby among the top clubs in Europe.
"He has a lot of experience for a 25-year-old prop and will bring a huge amount to our performance on the pitch and to the development of the talented young props we have at the club."
Nel has clearly been drawn to the club by Edinburgh's strong performance in this season's Heineken Cup which sees Bradley's side looking forward to a high-profile quarter-final against four-time champions, Toulouse, at Murrayfield on Saturday, 7 April (kick-off: 3.00pm).
Nel goes into the 2012 Super Rugby season with three years experience of the southern hemisphere's top club competition, having made 32 appearances since his debut against the Waratahs at the tail end of 2009.
He then starred in the club's journey to the Currie Cup final in which his highlight was undoubtedly a semi-final overpowering of Natal Sharks' South Africa internationalist Tendai 'Beast' Mtawarira.
Looking ahead to his summer switch Nel said: "My experience at the Cheetahs has been fantastic and I can't thank coach Naka Drotske enough for all that he has done for me but when I got the chance to go to Edinburgh Rugby, it was an opportunity to gain new experience and develop my game even further.
"Edinburgh Rugby play a fantastic brand of rugby and I'm really looking forward to lining up alongside some of their world-class players and living in a great city like Edinburgh.
"To be involved in that set-up and experience northern hemisphere rugby and conditions can only improve my game in two great competitions - the Rabodirect PRO12 and the Heineken Cup - and I'm certainly looking forward to the challenge."
Edinburgh Rugby Chief Executive, Craig Docherty, said: "The signing of WP Nel is a clear statement of intent from Edinburgh Rugby as we look to retain and recruit the right players that will help us build on the many strides made this season and to ensure that we continue this momentum into future years."