Commanding officer, also known as a C.O. is an officer who has command responsibility for a post - such as an installation, station, or a ship in both the United Earth Starfleet as well as the Federation Starfleet.

For most starship commands, a commanding officer will usually hold the rank of Captain, however this is not always the case. Individuals from the rank of Lieutenant all the way up to Admiral have been known to hold the post of commanding officer.

In 2364 the Bluegill parasites attempted a takeover of Starfleet, which was detected by a number of Starfleet officers. Learning of this possible conspiracy, Captain Jean-Luc Picard had Lt. Commander Data review all Starfleet orders for the past six months. In the course of his review, Data learned that there was among other things an uncustomary shuffling of commanding officers, with these new C.O.'s having frequent contact with the highest levels of Starfleet Command. (TNG episode: "Conspiracy")

Chronology

2151

• Captain Jonathan Archer takes command of Enterprise (NX-01)

2154

• Captain Erika Hernandez takes command of Columbia (NX-02)

2245

• Captain Robert April takes command of the USS Enterprise

2246

• Lieutenant Commander Gabriel Lorca takes command of the Starfleet Outpost on Tarsus IV.

2250

• Captain Christopher Pike takes command of the Enterprise

2263

• Commodore Matthew Decker commands the USS Constellation

2264

• Captain James T. Kirk takes command of the Enterprise
• Commodore Diego Reyes takes command of Starbase 47, aka Vanguard

2270

• Captain Willard Decker commands the Enterprise during a three-year refit, but never commands her on active duty

2273

• Admiral Kirk assumes command of the Enterprise during the V'Ger incident

2278

• Captain Morgan Bateson and the USS Bozeman enter a temporal causality loop

2285

• Captain Spock commands the Enterprise as a training vessel
• Admiral Kirk assumes command of the Enterprise to investigate a disturbance at station Regula I
• The Enterprise is destroyed over the Genesis Planet

2286

• Kirk is demoted to Captain and takes command of the USS Enterprise-A

2293

• The Enterprise-A is decommissioned
• Kirk resigns from Starfleet and buys the Enterprise-A. Soon after, it is destroyed over Chal
• Starfleet Captain John Harriman takes command of the USS Enterprise-B

2311

• Captain Demora Sulu takes command of the Enterprise-B

2332

• Captain Rachel Garrett assumes command of the USS Enterprise-C

2333

• Lieutenant Commander Jean-Luc Picard takes command of the USS Stargazer

2344

• Captain Benjamin Maxwell commands USS Rutledge

2355

• Captain Picard is victorious at the Battle of Maxia, but the Stargazer is lost

2364

• Captain Picard takes command of the USS Enterprise-D

2365

• Kathryn Janeway is transferred from command of the USS Bonestell to command of the USS Billings

2367

• Captain Benjamin Maxwell relinquishes command of the USS Phoenix to his first officer pending a court-martial

2368

• Captain Bateson and the USS Bozeman are released from the temporal causality loop

2369

• Captain Ileen Maisel commands the USS Marignano
• Commander Benjamin Sisko assumes command of station Deep Space 9.

2371

• The USS Defiant is assigned to the command of Commander Benjamin Sisko.
• The Enterprise-D crashes on Veridian III
• The USS Bozeman becomes a museum ship. Captain Bateson assumes command of the construction of the USS Enterprise-E
• Captain Janeway takes command of USS Voyager
• Captain John Lewinski commands the USS Monitor

2372

• Captain Picard takes command of the USS Enterprise-E
• Captain Bateson takes command of the USS Bozeman-A

2373

• Captain Mackenzie Calhoun takes command of the USS Excalibur
• Captain David Gold commands the USS da Vinci

2375

• Captain Klag takes command of the IKS Gorkon

2376

• The USS Excalibur is destroyed by a computer virus
• Captain Elizabeth Shelby takes command of the USS Exeter
• Captain Calhoun takes command of the USS Excalibur-A
• Captain Shelby takes command of the USS Trident

2378

• Captain Chakotay takes command of Voyager

2379

• Captain William T. Riker takes command of the USS Titan

2381

• Captain Ezri Dax takes command of the USS Aventine

3189

• Captain Michael Burnham takes command of the USS Discovery