The first five-eighth will come back from Japan to be one of three number 10s for the franchises. He replaces Fletcher Smith, who has gone to the Hurricanes.
Other new names include Waikato props Ayden Johnstone, Sef Fa'agase and Josh Iosefa-Scott and Hawke's Bay halfback Folau Fakatava.
There are seven players from Otago in the squad and for the first time ever no player signed with Southland makes the squad.
Banks first played for the Highlanders in 2015, kicking a dropped goal in the final in 2015 to seal the title for the side.
At the end of the 2016 season, Banks was set to move to Italy but he decided against that for personal reasons. After Hayden Parker was injured in pre-season, Banks, who was sitting at home, was called into the side and played a big part in the 2017 season, playing in 15 of 17 games and scoring 125 points.
Banks then went to Italy where played just the one season for the Benetton club, before moving to Japan to play for the NTT Docomo Red Hurricanes.
He is something of a cult figure in the south so his return is likely to be popular.
Head Coach Aaron Mauger is excited by the group he has assembled: "We have a well-balanced side with a degree of experience there, we blooded ten new players last season and I was excited to see the growth in those players during the Mitre 10 competition.
"The initial focus as always will be to execute a good pre-season and bring the team together for what will undoubtedly be another exciting challenge for the 2019 squad."
Full team:
Liam Coltman, Ash Dixon, Ray Niuia, Daniel Lienert-Brown, Josh Iosefa-Scott*, Ayden Johnstone *, Siate Tokolahi, Tyrel Lomax, Sef Fa’agase, Tom Franklin, Jackson Hemopo, Paripari Parkinson, Josh Dickson, Jack Whetton, Luke Whitelock, Liam Squire, James Lentjes, Dillon Hunt, Marino Mikaele Tu’u, Shannon Frizell, Elliot Dixon, Aaron Smith, Kayne Hammington, Folau Fakatava, Bryn Gatland, Josh Ioane, Marty Bank, Rob Thompson, Patelesio Tomkinson, Teihorangi Walden, Richard Buckman, Matt Faddes, Thomas Umaga-Jense, Waisake Naholo, Tevita Li, Tevita Nabura , Josh McKay , Ben Smith. Unavailable due to long term injury: Aki Seiuli, Kalolo Tuiloma
With NZME