Townsend (22), who captained the Junior Kangaroos in 2011, had a glittering NYC career with the Sharks making his NRL debut two years ago.
He was also courted by Melbourne, St George Illawarra and Penrith before deciding the Vodafone Warriors presented the best career move for him.
Head coach Matthew Elliott said Townsends all-round playmaking qualities and his goal-kicking ability set him apart.
Hes going to be of tremendous value to us from next season, he said.
Weve been watching him closely for some time and couldnt be happier to have secured his services for the next two years.
Townsend said he welcomed the opportunity to join the Vodafone Warriors.
Its a huge move for me having spent all my life in the shire (Cronulla) but I was hugely impressed with the Warriors recruitment approach, he said.
They did a fantastic job showing me what the club has to offer and also what a great place Auckland is to live in.
The Sharks have developed me but this is too good an opportunity to miss. I want to establish myself at NRL level and the Warriors will give me the best possible chance to do that.
Townsend has made 16 NRL appearances for Cronulla having played 55 times for the club in the NYC scoring 332 points.
Hell have a Cronulla team-mate in Auckland next year with the Vodafone Warriors recently signing Sharks back rower Jayson Bukuya.
While confirming Townsends signing today, Vodafone Warriors general manager football operations Dean Bell said halfback Harry Siejka had been granted an early release from his contract, effective immediately.
Harry told us hes been missing home and wants to return to Sydney, he said.
Its disappointing it hasnt worked out for him here but he has been a model professional and wed like to wish him all the best for the future.
Siejka has been a regular for the Auckland Vulcans in the New South Wales Cup this season.
Date of Birth: January 10, 1991
Birthplace: Sydney, NSW
Junior Club: Yarrawarrah Tigers
Rep Honours: Junior Kangaroos 2011
NRL Debut: Cronulla v Brisbane, Toyota Stadium, June 03, 2011 (Round 13)
NRL Games: 16 (2011-2013), 68 points (3 tries, 28 goals)