Starfleet casualties (23rd century)
Federation Starfleet personnel in the 23rd century often had to place their lives in danger during the course of their duties, and many made the ultimate sacrifice.
For non-Starfleet casualties sustained by the Federation, see Civilian casualties.

Posts 
In alphabetical order by date.

USS Discovery 
The following casualties served aboard the  while it was in service (2256 –):

Revivals

USS Enterprise (NCC-1701) 
The following casualties served aboard the  while it was in service (2245 – 2285):

Captain Christopher Pike's five-year mission 
 Three crewmembers perished on Rigel VII, including Christopher Pike's personal yeoman, in 2254. ()
 Seven crewmembers reported dead during the battle to stop Control. ()

Captain James T. Kirk's five-year mission 
In addition to the those listed below:
Nine perished after contact with the galactic barrier in 2265 ()
One crewman killed by the dikironium cloud creature aboard the Enterprise in 2268 ()
Three crewmen died of Rigelian fever in 2269 () 
See also: Mirror universe casualties

Revivals

Following the 2270s refit 
In addition to those listed below:
One security guard killed by V'Ger in the 2270s. () *This directly contradicted by Kirk at the end of the movie when Starfleet requests casualties and ship status. "Report two casualties: Lieutenant Ilia... Captain Decker. Correction. They're not casualties. List them as missing."
The Enterprise took high casualties in 2285 during the Battle of the Mutara Nebula with Khan Noonien Singh. ()

Revivals

Other posts 
In addition to those listed below: 
 Unknown number of crewman of the starships , , and  killed in the Battle of the Binary Stars. (2256)
 Unknown number of  personnel killed in the Battle of the Binary Stars. (2256)

In addition to, and including, those listed above:

2217
 listed as MIS (missing in space).

2257
 suffered nearly two hundred deaths to a dikironium cloud creature.

2266
Twenty died aboard the Antares when the ship was destroyed.
Neutral Zone Incursion
Outpost 2 destroyed with all hands by the Romulans.
Outpost 3 destroyed with all hands by the Romulans.
Outpost 4 destroyed with all hands by the Romulans.
Outpost 8 destroyed with all hands by the Romulans.

2267
The entire crew of the  (approximately 430) killed when the planet killer destroyed the planet L-374 III.
The entire Starfleet contingent stationed on the Cestus III colony – save sole survivor Lieutenant Harold – was killed by the Gorn, along with the colony's population.

2268
The entire crew of the  died when the ship encountered a giant spacefaring amoeba.
The entire crew of the  died when the M-5 multitronic unit assaulted the ship.
53 died on USS Lexington When m5 assaulted the ship
The entire crew of the , except for Captain Ronald Tracey, died from a bacterial disease at Omega IV.
The entire crew of the  died when the ship was trapped in spatial interphase in Tholian space.

2270s
The entire staff of Epsilon IX station died in V'Gers attack.

2285
The entire crew of the  died when the ship was destroyed at the , except for Lt. Saavik.

2294
 The captain and crew (except for Captain Scott and Ensign Franklin) of the  died when the ship crash landed onto a Dyson sphere.

Revivals

External link 
 
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