The Sharks have agreed to release Waylon Murray to allow the centre to join the Lions.
Murray's contract with the Sharks was due to run until October but he has now been freed to move to Johannesburg ahead of the Currie Cup.
Murray, who has spent five season with the Sharks, has agreed a two-year deal at the Lions and his relishing the chance to work with the likes of John Mitchell and Dick Muir.
"I've been in discussions to join the Lions for a while, and I made the decision two years ago to move to Johannesburg," he said.
"I officially signed this morning and I hope I will be able to contribute during my time here.
"I'm still young and I want to further myself and get back to how I was playing a few years ago.
"I've met John [Mitchell] a few times as he's visited the Sharks over the years, and he's a really great guy. I'm very excited about working with him.
"I've also worked with Dick [Muir] in the past, and we have a great relationship. He really knows how to get the best out of his players, and I can't wait to work with him again."