The news comes as no surprise after Sky successfully trialled the use of both as leaders at the Tour of the Alps which lead to Thomas taking victory and Landa riding in support.
The team has seemingly learned from the mistakes of last year's Giro when Landa dropped out after suffering from a fever leaving the team leaderless, and will be hedging their bets with both Landa and Thomas in 2017.
Landa and Thomas will be supported by a strong team of climbing domestiques, including Philip Deignan, Kenny Elissonde, Sebasian Henao, and Vasil Kiryienka.
However the there is no space for Italian sprinter Elia Viviani, who has thirteen top-ten finishes, including one win, in bunch sprints at the race.
Watch: Giro d'Italia 2017 essential guide
Thomas enjoyed victory at the Tour of the Alps, but will face a much stronger field at the Giro, with 2016 champion Vincenzo Nibali hoping to secure another Grand Tour victory with his new team, Bahrain-Merida.
Nairo Quintana (Movistar) will also be riding, hoping to become the first person this side of the millennium to win the Giro/Tour double.
Other notable names like last year's breakthrough star, Steven Kruijswijk, will want to impress, and Orica-Scott's Adam Yates will want to go even better than his performance at the 2016 Tour de France, where he finished fourth.
Full Team Sky squad for the Giro d'Italia:
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