Starfleet uniform
Starfleet uniforms were uniforms worn by individuals serving in the Federation Starfleet, originally a United Earth organization. These uniforms facilitated the wearers' needs as both scientists and researchers, as well as Starfleet's military role. The uniform and combadge used by Starfleet personnel may vary by the ship or facility they were assigned to, or the officer's rank or department. These were often retained even when visiting other Federation locations. (; ; ; ) 

Casual duty attire also allowed for considerable variation of uniform aboard a Starfleet vessel, though it was ultimately up to the captain's discretion. Wearers were expected to abide by the Starfleet dress code, though special exceptions were sometimes made for certain aspects of an individual's cultural heritage, such as Worf's Klingon baldric, Nog's Ferengi headdress, and the earrings of Ro Laren, Kira Nerys, and Shaxs. (, et al.) According to Elim Garak, "I think Starfleet should allow their officers more latitude in accessorizing their uniforms. You'd be surprised what a nice scarf can do." () 

On two occasions the term "Federation uniform" was used to describe Starfleet uniforms. 

In 2369, the Bajoran civilian, Mullibok, who was being evicted from his home, asked Commander Benjamin Sisko how many Federation uniforms he planned on sending down to have him removed. () 

In 2372, Chakotay referred to his as a Federation uniform as he explained to Kar how it was like the Jal name that the Kazon earned. Chakotay told him that his uniform was earned through "years of study", and "learning about science and ships and navigation," adding too, that he was further taught to be "[..] prepared us to defend ourselves in battle. They prepared us very well. And we had to pass many difficult tests before we were given the right to wear the uniform." ()

Divisions
Starfleet uniforms were classified by color among the command, sciences, and operations divisions. Occasionally, the uniforms were also broken down by department, while displaying rank insignia conspicuously. The color scheme had varied over time throughout Starfleet history, but the uniforms were designed for comfort even in the most extreme environments. ()

Command
The command division was the head of Starfleet, with most of the ranking officers in Starfleet Command wearing these colors. Generally, this division was responsible for the administration of starships, starbases, and space stations.

Operations
The operations division was the backbone of Starfleet, encompassing the engineering, security, and support departments. This division was responsible for technological innovation and for maintaining and defending the Federation.

Sciences
The sciences division was the heart of Starfleet, composed of the exploratory, medical, and mental health departments.

Uniform styles

Unknown eras
These Starfleet uniforms were introduced between the 24th and 31st centuries.

Type #1 

This uniform was worn by one of 's hosts. ()

Type #2 

This uniform was worn by officers in an unknown era. ()

Type #3 

This uniform was worn by the delegation welcoming the Kelpien and Ba'ul Alliance into the Federation. ()

In the 23rd century, similar uniforms had been in use as cadet outfits. ()

Uniform variations

Some officers wore alternate uniforms. Deanna Troi often wore casual clothing while on duty, and T'Pol retained her original Vulcan uniform with a few concessions to her Starfleet rank and ship assignment. Other officers, such as Worf, Montgomery Scott, and Ro Laren, were allowed to wear accessories relating to their culture with their uniforms, but this was at the discretion of the captain. Uniforms were also altered to accommodate non-humanoid officers, such as the three-armed, three-legged uniform of the Edosian Arex, and the uniforms for beluga whales Kimolu and Matt. (; ; ; ; )

Uniforms were also adapted to environmental or atmospheric conditions. When exploring the planet , Benjamin Sisko and colleagues wore long, flowing gown uniforms to deal with the sand. They featured a colored stripe to represent departments. ()

Dress uniforms

Dress uniforms were a variant of the standard Starfleet uniforms worn for special occasions, such as weddings, courts martial, funerals, and the greeting of ambassadorial delegations and heads of state. (; ; ; ; )

Appendices

Background information
Patrick Stewart's character of Jean-Luc Picard has appeared in more styles of Starfleet uniform than any other character on screen without story contrivances (like time travel, holodecks, or alternate timelines) being involved.

For most of Star Treks history, Starfleet uniforms have had at least three division colors. Some characters have worn different division colors in different episodes. Leslie, Jae, Tom Paris, Harry Kim, and Sylvia Tilly have each been shown wearing three colors at different points (including, for Paris and Kim, alternate timelines and holodeck scenarios); however, the first character to wear all three division colors in one episode was Ensign Sam Rutherford, who wore operations gold, command red, and medical blue in .

Design
The Starfleet uniforms worn during  were designed by William Ware Theiss, who returned to design the  uniforms (which were further adapted into future versions on , , and the TNG-era films by Robert Blackman). Robert Fletcher designed the uniforms seen throughout the original series movies, with later new designs provided by Nilo Rodis. 

Robert Blackman also designed uniforms worn on , a design representing a precursor to those seen in TOS. The uniforms seen in  were designed by Gersha Phillips. The uniforms in  were designed by Christine Clark.

Michael Kaplan designed the uniforms seen in  and , and Sanja Hays designed the uniforms for .

As shown in the It's A Wrap! sale and auction, a number of Starfleet uniforms have had padding to increase muscular appearance. Such cases include two costumes for Tom Paris, one racquetball costume for Julian Bashir, and a Deep Space Nine costume for Worf, to create a more Klingon appearance. According to Wil Wheaton, all the main cast members wore muscle padding during the first two seasons of The Next Generation, mainly because of the tight-fitting nature of the spandex uniforms used in these two seasons. 

Several prototype uniform undershirts to those seen in  on were sold off on the It's A Wrap! sale and auction on eBay.

Ambiguous uniform

A Human female seen as a member of the Elysian Council in  wore a uniform of ambiguous origin. It was described in the Star Trek Concordance as "a white suit with blue collar and an insignia on the left breast," and was suggested to "possibly [be] an early Star Fleet [sic] uniform". While it is known that the , and possibly other Earth/Federation ships, were lost in the years prior to 2269, it is unclear if this is indeed a Starfleet uniform, and, if so, from which era it originated.

External links

de:Sternenflottenuniform
ja:宇宙艦隊の制服
ru:Униформа Звёздного флота