AZ coach Co Adriaanse has previously worked with Landzaat during his time at Willem II and is delighted to renew acquaintances with the talented midfielder.
Willem II had previously resisted offers for the player, but have succumbed to AZ's offer, finally allowing the midfield-man an opportunity to play on a bigger stage.
Feyenoord and Ajax have shown interest in the 27-year-old in recent seasons, but were put off by Willem II's demands.
Landzaat's signing comes in a period of transition for AZ, with experienced centre-back Peter Wijker having been told that he will not be offered a new deal when his current contract expires.
Wijker will most likely leave AZ in the summer, along with Alair Cruz Vicente, Jamal Dibi, Canigia and Hans van der Woude, who will all be free agents in the summer.
