- For other uses, see J class starship.
In the year 2266, Harcourt Fenton Mudd possessed an unregistered ship of this type, which was destroyed in an asteroid belt while being pursued by the Federation Starfleet Constitution-class starship USS Enterprise. (TOS episode: "Mudd's Women")
In 2274, shortly after the Phaetonian crew of the USS Icarus went insane from traveling through the galactic barrier, Captain Kadan fired upon and destroyed a manned class J cargo ship. (TOS comic: "Eclipse of Reason").
- Mudd's ship
Two vessels similar in appearance to Mudd's cargo ship appeared in Original Series episodes. The cgi model of Mudd's ship was reused to represent a one-man ship of Denevan design in "Operation -- Annihilate!" The model was subsequently altered to include bigger warp engines and several large windows for an appearance as the Aurora (NC-17740) in "The Way to Eden." Neither ship was identified as Class J.