A beard is a growth of facial hair which was common among humanoids. In numerous species, such as Humans, the growth of facial hair is a secondary sexual characteristic of the male of the species. Not all males allow their beards to grow, and they are generally removed by shaving them regularly. (TNG: "Code of Honor") Most also wear Tellarites wear beards.
Data experimented with wearing what he described as "a fine, full, dignified beard" in early 2365. Data felt that such a beard "commands respect and projects thoughtfulness and dignity." His crewmates described his beard as being "very different", and were especially amused after Data began stroking it and inquiring where such actions made him appear more intellectual. (TNG: "The Schizoid Man")
Beverly Crusher believed that with the invention of the razor, beards had become little more than an affectation. She attempted to goad bearded Riker, Worf and Geordi La Forge into betting a clean shave in a round of poker. The game was interrupted by a page for the senior staff, however. (TNG: "The Quality of Life")
Facial hair was a common evil trait in Human storytelling. In the wake of Admiral Norah Satie's witch-hunts in 2367, Captain Jean-Luc Picard told Lieutenant Worf, who was disgusted with his own conduct (he had strongly supported, and even assisted, her investigations until she made an accusation against Picard which he knew to be false), that "villains who twirl their mustaches are easy to spot. Those who clothe themselves in good deeds are well camouflaged". (TNG: "The Drumhead")
Worf regularly had his beard cut in Mot's barbershop aboard the USS Enterprise-D. (TNG: "Schisms") When Worf's adopted mother, Helena Rozhenko, noticed "a touch of gray" in his beard, she reassured him that "Rozhenko men have always had beards of iron gray." (TNG: "New Ground")
Bajorans
Bajorans are capable of growing beards. Although not necessarily required for religious reasons, some Bajoran monks and ranjens wear beards. (Star Trek: Deep Space Nine)
Notable male Bajorans with beards:
Humans
Humans are also capable of growing beards.
In 2365, William Riker grew a beard, having grown annoyed at people telling him how young he looked. Q made light of it, commenting that Riker was never so stolid "before the beard". (TNG: "Deja Q", "The Pegasus") Riker kept the beard for a decade until 2375, when he shaved it off at Deanna Troi's suggestion. After the shave Data was somewhat skeptical of his friend's newly clean-shaven appearance. (Star Trek: Insurrection) Riker eventually regrew his beard. (Star Trek Nemesis)
Benjamin Sisko shaved his head and began growing a goatee while visiting Bajor in 2371. His son, Jake Sisko, took note of the goatee and asked him what it was, to which the elder Sisko stated that he felt it "was time for a change." The elder Sisko asked his son what he thought of it, to which Jake replied that he liked it. (DS9: "Explorers")
In an alternate timeline in which Earth was destroyed by the Xindi superweapon, Enterprise armory officer Malcolm Reed wore a style of beard known as a "circle beard" or "moutee" in 2165. (ENT: "Twilight")
Notable male Humans with beards:
- Argyle
- Biddle Coleridge
- Flint (as Leonardo da Vinci among others)
- Maury Ginsberg
- Ira Graves
- Jack
- Jack Hayes
- Miklos Karlovassi
- Kodos the Executioner
- Geordi La Forge
- Frederick La Rouque
- Leyton
- Abraham Lincoln
- Paul Manheim
- Leonard McCoy
- Tom Norris
- O'Shea
- William T. Riker
- Thomas Riker
- Roy Ritterhouse
- Jackson Roykirk
- Sergey Rozhenko
- Benny Russell
- Benjamin Sisko
- Cooper Smith
- John Torres
- Black (in the mirror universe)
- Gardner (in the mirror universe)
- Jean-Luc Picard (in an alternate timeline)
- Malcolm Reed (in an alternate timeline)
Klingons
Klingons find beards to be a symbol of courage. (TNG: "The Quality of Life") Most Klingon males have short beards, but do not generally have associated sideburns. This is apparently a stylistic choice, as some Klingons, such as Kras and Gorkon, did have sideburns. (TOS: "Friday's Child"; Star Trek VI: The Undiscovered Country)
Notable Male Klingons without beards:
Vulcans
Vulcans, and presumably Romulans, are also capable of growing beards. Some Vulcan masters and other religious figures grow short goatees or full beards. (VOY: "Gravity"; Star Trek V: The Final Frontier)
In the Mirror universe, both Soval and Spock wore similar short goatees while they were members of the Terran Empire Starfleet. (ENT: "In a Mirror, Darkly"; TOS: "Mirror, Mirror")
Notable male Vulcans with beards:
- Sybok
- Soval (in the mirror universe)
- Spock (in the mirror universe)
- Vulcan Healer of the 23rd century
- Vulcan Master of the 23rd century