Langman will fill the Swifts' import player role after two seasons with the Northern Mystics and a stellar career at Waikato-Bay of Plenty Magic, where she was part of their 2012 title-winning team.
Langman, 29, has amassed more than 100 Tests for New Zealand and is the most capped player in the ANZ Championship with 120 appearances.
Swifts coach Rob Wright said Langman was a key signing.
"Laura is the complete netball package. Not only is she a supreme athlete who excels at all three midcourt positions, she has a winner's mentality, is globally respected and a true leader," she said.
Langman said she was looking forward to joining the Swifts, who lost this year's grand final to the Queensland Firebirds 57-56.
"I want to keep challenging myself and my netball, and I see this move as a once-in-a-lifetime opportunity," she said.
"The Swifts played inspired netball in getting to the grand final last season and are determined to go one better, something I can't wait to be a part of."
Langman will replace Jade Clarke as the Swifts import player next season.
