Openside flanker Holah was the most-capped Chief in the 2007 squad with 81 caps, and is renowned as a hard tackling, high work-rate defender who will bring a wealth of experience to the Ospreys back row.
Marty has most recently captained a successful Junior All Blacks (New Zealand A) side which won the Pacific Nations Rugby Cup.
Comment from Director of Rugby, Kevin Hopkins:
"We are delighted to be able to confirm the signing of Marty Holah. He is a top quality International player and his signing signals another important step towards our aim to be a far more competitive team in European Rugby. Marty will bring a wealth of experience to our squad ahead of what is already an eagerly anticipated season. We are making great progress in finalising our squad for the upcoming season, and this is another key piece of the jigsaw."
Commenting on his move to the Ospreys, Marty Holah said:
"I am excited by the new challenge that awaits me in playing for the Ospreys and playing in Europe. The Ospreys have put together a very formidable side over the last few years, and to win the Magners League twice in three years speaks for itself. I was also impressed during my conversations with Mike Cuddy and Lyn Jones at the ambition that the Club has, particularly to win the Heineken Cup. Having come from a region like Waikato where we have had some good success recently, but are still looking to get better, that was an important factor in making my decision. I am looking forward to joining the team for the first round of the Heineken Cup and settling in to life in Wales."