The 26 year-old, whose brother Aaron is a current member of the Kiwi international set-up, joins the Kingsholm club from Super 12 side the Crusaders.
Commenting on www.gloucesterrugbyclub.com director of rugby Nigel Melville said: 'Nathan is a quality player and we've been in discussions with him for a number of weeks now. It's good to finally have him here ready for pre-season.
'We met up at Kingsholm a couple of months ago, and Nathan came over to England at the weekend to confirm everything. He joined us at the Compass Group Sevens event, which gave him a good chance to see some of the guys on the field, especially as we won the event.'
Mauger will be classed as an overseas player in the short-term, whilst his management team progress with a French passport, that is linked to relations on his mother's side of the family.
The former Crusaders midfield man, who played two games for the All Blacks during their tour of Europe in 2001, was delighted to arrive in Gloucester.
Talking to www.gloucesterrugbyclub.com he said: 'I came over to Gloucester to meet up with Nigel Melville and look around Kingsholm earlier in the summer and I liked what I saw.'
Mauger, who has worked with the Club's new fitness expert Mike Anthony whilst at the Crusaders and Canterbury, added: 'It's a great chance to come over to England and link-up with one of the top sides in the country.
'From what I've seen and heard from people Gloucester is a superb rugby environment and I'm looking forward to meeting the players and settling in.'
Nathan Mauger Profile:
Date of birth: 08.04.78
Previous clubs: Crusaders (Super 12) and Centerbury (NPC)