Unnamed Mars class starships
List of unnamed Federation starships of the .

Sustaining Federation Headquarters (3189) 
When the  first found Federation Headquarters in 3189, at least one Mars-class starship supported the cloaking field, which Nhan theorized may be a scout ship. ()

This ship, or another of this class, was also present while Discovery was undergoing refit, and had its warp nacelles replaced with disconnected warp nacelle technology. This ship would also have been present for Fleet Admiral Charles Vance's briefing of Starfleet Captains until Booker's ship arrived on auto-navigation. This ship was also visible on a diagram Vance and Lieutenant Audrey Willa were examining when Captain Saru met with them. ()

Battle at Federation Headquarters 
This ship, or another of the same class, was within the Federation Headquarters cloaking field when Osyraa was able to enter it aboard Discovery, and participated in the Battle at Federation Headquarters with Osyraa (commanding Discovery.) ()

Archer Spacedock 

A Mars-class starship was docked at Archer Spacedock along with the  and a  starship during the reopening ceremony of Starfleet Academy in 3190. ()

Docked at Federation Headquarters (3190) 
A ship of this class was nearby Federation Headquarters when Doctor Kovich issued instructions to Sylvia Tilly. ()

Mars class