Maitland, a powerful wing or fullback, has signed a deal with the Warriors until May 2015, according to the club's website.
He stormed to prominence for the Crusaders in 2010 - including an impressive performance at Twickenham against the Sharks - but has since struggled with injury. A broken hand ruled him out of almost all of Canterbury's season in the ITM Cup.
"We're delighted to be welcoming a player of Sean Maitland's calibre to Glasgow Warriors," Glasgow coach Gregor Townsend told the club's website.
"The back three is an area of the team where we already have a number of excellent options, and Sean will provide a further layer of quality as we enter another busy phase of the season.
"His try-scoring record in Super Rugby speaks for itself, and he's also a player who has a big appetite for self-improvement.
"He will be a fantastic addition to our squad and will, I'm sure, be very popular with our supporters."
Maitland, who has a Scottish grandfather, has scored 24 tries in Super Rugby and represented New Zealand Maori in 2010.
Townsend told Radio Live this morning that Glasgow had been chasing Maitland for more than two years.
