Berry, 27, joined Wasps two seasons ago from Racing Metro and had made 40 appearances to date.
With Joe Simpson ruled out through injury, Berry will play an increasingly important role in the season run-in.
The Australian said: "I am delighted to have renewed my contract with Wasps. Though we've had a tough season so far I totally believe we have the coaching staff and players to restore the club to where it should be.
"Both my wife and I have made some great friends through the club and we are excited to be extending our stay here in London."
Director of rugby at Wasps Dai Young added: "I have been really impressed with Nic this season. He is a talented number nine with a great attitude and I'm delighted that he's staying here.
"We've got a pool of very good scrum-halves in places for next season and that competition for places is extremely healthy."
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The Barbarians are one of the top invitational rugby sides with a long history and classic rugby jersey.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Lions get ready for their matches with this green training jersey. It's what the players wear. Get in the Gear!
A cool looking all black rugby cleat with the high performance adidas is known for. Get in the Gear!
Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
The Lions are ready to get their Australia tour underway. They arrive in Perth on Monday.
The New Zealand All Blacks training jersey for 2013/14. Get in the Gear!
The USA Rugby Pro Alternate rugby jersey is perfect for any fan of the Eagles. Get yours to wear during the summer Test matches.
The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.