Two individual seats in the rear provide a particularly comfortable experience in the second row. These seats are well-liked for their extensive lateral support which comes from the contouring. There is a roomy stowage compartment in the centre armrest between the two seats, which if desired can also contain a cup holder for a bottle. An electrically-operated rear-window blind for the rear passengers is also available as an option, which can palpably and measurably reduce sunlight streaming in at the touch of a button. It is fixed to the C-pillars, as it is in the S-Class.

For the first time Mercedes-Benz is offering the Mercedes-Benz CLS-Class with ISOFIX, the international standard securing system for child seats. The mechanism is fitted as standard and comprises two retaining brackets in each rear seat position, in the gap between the back rest and seat cushion, as well as an additional third anchor point above the backrest, the so-called top tether.