Work on 16 bi-level domed cars will cover lighting, plumbing, seating, ventilation, air conditioning and other components. It is expected to be completed in 2018.
Montreal-based engineering firm Canarail has been hired as prime contractor, with much of the work to be done in New Richmond in the Gaspé.
The agreement with Canarail follows a pilot project completed in 2013 and positive feedback from travellers, the companies said in a news release.
The refurbishment is the largest capital investment in Rocky Mountaineer's 25-year history, the firm said. It did not release cost figures for the work.
Rocky Mountaineer says it has carried more than 1.5 million travellers from around the world since being launched in 1990. Its season runs from the end of April to early October.