The trains, which were launched this summer, offer more legroom and improved catering. TV, cinema, press and radio ads will break initially in the Yorkshire region before being rolled out nationally.
The campaign is the first work by Vallance Carruthers Coleman Priest since it won GNER's advertising account earlier this year.
Separately, the Association of Train Operating Companies (ATOC) is offering travellers two-for-one entrance to a number of London attractions. A six-figure TV, radio and direct campaign will support the promotion.