Memory Alpha
Memory Alpha
Multiple realities
(covers information from several alternate timelines)

A list of unnamed Federation starships of the Nebula-class.

Wolf 359 starship

Battle damaged, Nebula-class starship adrift in space

The Nebula-class wreck on fire

This starship was destroyed in the Battle of Wolf 359. The wreck of this ship was adrift in space near the Borg cube when the USS Saratoga was destroyed. (DS9: "Emissary") The wreck was on fire by the time the USS Enterprise-D arrived at the site of the battle. (TNG: "The Best of Both Worlds, Part II")

While illegible in both episodes, this starship model was labeled as the USS Melbourne (NCC-62043). [1] An Excelsior-class starship was also named USS Melbourne in the "Emissary". This ship is listed as unnamed, because Memory Alpha considers that the name of this ship has been retconned. See USS Melbourne for more information about the model and the naming issue.
According to the short story "Trust Yourself When All Men Doubt You" in The Sky's the Limit, this Nebula-class Melbourne was constructed to replace the other Excelsior-class Melbourne. The Star Trek Encyclopedia, however, doesn't mention this Nebula-class Melbourne, because it was not the intention that there would have been two different ships with the same name.

The hulk of an unnamed Nebula-class starship

The hulk of this vessel was later stored, by 2368, at Surplus Depot Z15 in orbit of Qualor II. (TNG: "Unification I")

The footage of this vessel in "Unification I" was a reuse of the footage from the Wolf 359 debris field from "The Best of Both Worlds, Part II", though the damaged sections of the hull were clearly on fire in the "Best of Both Worlds, Part II" version.

Pursuit vessel

An unnamed Nebula-class chases the USS Yellowstone

In 2372 of an alternate timeline this starship pursued the USS Yellowstone runabout after it was stolen from spacedock by Harry Kim and Tom Paris. Its captain hailed Paris and Kim and asked them to stand down.

Initially the ship was disabled as it passed through a cloud of tetryon plasma, but later caught up with the Yellowstone and subsequently damaged the runabout's warp drive, causing the runabout's destruction. (VOY: "Non Sequitur")

Deep Space 9 visitor

Docked at Deep Space 9

In alternate 2373, this starship was docked at Deep Space 9's upper pylon when the space station's civilian population began leaving en mass, following the recommending of voluntary resettlement. (DS9: "The Visitor")

According to the script notes, there was "Unusual activity evident, with transports and runabouts arriving and departing."

Battle of Sector 001

An unnamed Nebula-class starship attacking the Borg

In 2373, this starship fought against the Borg in the Battle of Sector 001.

It joined in the assault on the Borg cube, led by the USS Enterprise-E, by firing several photon torpedoes at the coordinates defined by Captain Jean-Luc Picard. (Star Trek: First Contact)

Although not identified visually, it is possible that this ship is the otherwise-mentioned USS Lexington, which was referenced in comm chatter during the engagement.
On the other hand, it is concurrently possible that this ship was the USS Endeavour (NCC-71805), as per the Star Trek Encyclopedia (3rd ed, p. 135). Some prints of Star Trek: First Contact do not include shots of this vessel.
This appearance marked the last time that use was made of the physical studio model as a production asset. With the exception of the USS Enterprise-E, all other Federation starships in the sequence where executed as CGI models. For further information on the model, see Nebula-class model.

Earth transport

Transport docked at Deep Space 9

Later in 2373, this starship served as a transport from Deep Space 9 to Earth.

Among the passengers aboard this vessel were Lewis Zimmerman and Amsha and Richard Bashir. (DS9: "Doctor Bashir, I Presume")

This unidentified vessel reused footage of the USS Prometheus from "Second Sight", still being the physical studio model, and was referenced in the script simply as "a Federation transport ship."

Operation Return

A Nebula-class starship at Deep Space 9

In 2374, this starship was parked near Deep Space 9, following Operation Return, along with the USS Defiant, the USS Yeager, and the USS Farragut. (DS9: "Sacrifice of Angels")

Second Battle of Chin'toka

These two starships participated in the second Battle of Chin'toka, where they were both destroyed during the battle by the Breen's devastating energy dampening weapon. (DS9: "The Changing Face of Evil")

This and the subsequent appearances are reuses of the CGI model of the Nebula-class. That model had made its debut in the earlier Star Trek: Voyager season four episode "Message in a Bottle" and is identifiable as such for its oval shaped navigational deflector dish housing.

Invasion of Cardassia

These two starships fought at the Battle of Cardassia. Following the battle, they waited with other Federation, Romulan, Klingon, and Cardassian ships to launch an offensive against the Dominion forces on and in orbit of Cardassia Prime. (DS9: "What You Leave Behind")