Q distributes cigars to celebrate his return to the Q Continuum
Smoking is the act of igniting a substance in order to inhale the by-products of the thermal and chemical reaction to fire released in smoke. Some narcotic chemicals and medicines can be inhaled in this manner. On Earth, it was the traditional way of consuming tobacco, a practice that can be traced back to the peace pipe rituals of some Native American groups.
While once a popular and dangerous habit on Earth, the smoking of tobacco had decreased by the time of Starfleet and may have been abandoned completely by Humans by the 2370s.
In 1893, Samuel Clemens was smoking a cigar at the literary reception for Guinan in San Francisco. (TNG: "Time's Arrow")
In 1957, a cigarette machine was located in the Pine Tree bar in Carbon Creek. (ENT: "Carbon Creek")
Dr. Nichols, plant manager of Plexicorp, wore a pin on his sweater that read "I quit smoking". (Star Trek IV: The Voyage Home)
St. John Talbot smoking
In 2004, Loomis, nervous about Xindi-Reptilians finding out he was helping Jonathan Archer find out more about them, starting smoking to calm himself. T'Pol, however, was disgusted by him smoking and asked him to put it out. When he told her to open the window in his car, she promptly put a phase pistol to his head and he put out the cigarette. (ENT: "Carpenter Street")
In 2153, some of the patrons of a saloon on a Skagaran colony were smoking. (ENT: "North Star")
A "No Smoking" sign was visible in the medical laboratory on Miri's planet in 2266. (TOS: "Miri")
"No smoking" sign visible
According to signs posted in the transporter room of the USS Enterprise in the 2280s, smoking was prohibited in that area. Smoking was also prohibited in the Mark IV bridge simulator. (Star Trek II: The Wrath of Khan)
The Banean Lidell Ren smoking
After traveling back in time to the 20th century Earth, Quark, Rom, and Nog were baffled that Humans of the time would inhale poison in this way. Quark was especially excited, stating that if humans bought poison, they'd buy anything. (DS9: "Little Green Men")
St. John Talbot, the Federation representative at the "Planet of Galactic Peace," Nimbus III, was a smoker at the time of Sybok's occupation of Paradise City. (Star Trek V: The Final Frontier)
Inmates on Rura Penthe smoked cigars to keep warm, although it wasn't clear what form of matter was being smoked. (Star Trek VI: The Undiscovered Country)
Some members of the Banean species smoke. When Tom Paris saw Lidell Ren smoking in 2371, he made the ethnocentric statement: "Smoking is a bad habit. My species gave it up centuries ago when we finally got it into our heads it was killing us". (VOY: "Ex Post Facto")
In the holoprogram "Julian Bashir, Secret Agent", the character of Duchamps smoked cigars.(DS9: "Our Man Bashir") In another of Bashir's holoprograms, "Bashir 62" the character Lola Chrystal, a facsimile of Kira Nerys, lit a cigarette and blew the smoke flirtatiously at Odo. (DS9: "His Way")
Mr. Duchamps with a cigar
Fictional characters of the Dixon Hill novels and stories also smoked. When Jean-Luc Picard played the role of Hill in the holoprogram version, he was offered a cigarette on at least two occasions. (TNG: "The Big Goodbye", "Manhunt") Nicky the Nose was another character seen smoking as well as several nightclub patrons. (Star Trek: First Contact)
Guinan, who appeared as Gloria in the Dixon Hill program, smoked a cigarette when she entered the program in 2367. (TNG: "Clues")
Also in the holodeck, Deanna Troi smoked a cigar while in character as Durango, the mysterious stranger who comes to Sheriff Worf's aid in the town of Deadwood, (TNG: "A Fistful of Datas") and Data occasionally smoked a pipe in the role of Sherlock Holmes. (TNG: "Lonely Among Us", "Elementary, Dear Data", "Ship in a Bottle")
In a vision of 1953 New York City sent by Prophets to Captain Benjamin Sisko in 2374, both Julius Eaton and Roy Ritterhouse were smokers (Eaton smoked cigarettes, Ritterhouse cigars). (DS9: "Far Beyond the Stars")
Background
Scott Bakula in an outtake
In Star Trek II: The Wrath of Khan, director Nicholas Meyer had "No Smoking" signs posted on the bridge of the Enterprise. According to the text commentary for the film, at Gene Roddenberry's insistence, they were removed. Roddenberry felt that enlightened future Humans would not have hang-ups or addictions like smoking. The "No Smoking" sign can still be seen on the bridge in the opening "Kobayashi Maru" scene.
In the "Outtakes" section of ENT Season 1 DVD a scene appears in which Scott Bakula should enter Jolene Blalock's quarters, but not like in the episode, he waited behind the door with two drinks and was smoking a cigarette.
Among the items which were sold off on the It's A Wrap! sale and auction on eBay, was a cigar traveler humidor which stood in for a set dressing container in an episode of Star Trek: Enterprise. The original tag of the container says "Cigar Traveler Co., Carson City, Nevada". [1]