Contract details have now been ironed out and the talented number nine will meet up with his new team-mates on Monday.
Ospreys' Elite Performance Director Andrew Hore had nothing but praise for the half-back who is eager to begin his new career in the northern hemisphere.
"As a person and a player, he has an excellent work ethic and sets very high standards on and off the pitch," he said.
"The esteem in which Jamie is held in his home country is clear as the NZRU were so keen to keep hold of him.
"Jamie has a wealth of Super 12 and 14 experience with both the Chiefs and the Crusaders, as well as playing for New Zealand A - that experience can only be of benefit to the region.
"His enthusiasm and professionalism rubs off on others and he shares the same core values as the Ospreys, which is one of the main reasons why he is so keen to join us.
"His arrival will give us another option at scrum half, providing real competition for Mike Phillips and increasing the strength in depth of our squad."



