Played by: Armin Shimerman
Position/occupation: Proprietor of Quark's Place, a bar, casino, and holo-entertainment center on Deep Space Nine
Birthplace or childhood home: Ferenginar
Parents: Keldar (father, deceased); Ishka (mother)
Siblings: Rom (younger brother)
Love interests: Natima Lang, Grilka (more of a lust interest, actually), Jadzia Dax, Ezri Dax
Other family: Nog (nephew); Firn, Gorad (uncles); Barbo, Gaila, Kono, Stol (cousins)
Hobbies/likes/interests: An accomplished lockpick and computer hacker.
Dislikes: Bajoran synthale; root beer (which he despised as a symbol of Federation values)
After leaving home on reaching his Age of Ascension, Quark was apprentice to a district sub-nagus until he apparently was caught having sex with the boss's sister. Then he worked on a Ferengi long-haul freighter for eight years as a ship's cook, until he finally bought a bar on a Cardassian space station orbiting Bajor, and settled there, in 2363. At about that time, Quark had an affair with a Cardassian named Natima Lang, who left him after he used her codes to steal from her employers.
When a Bajoran chemist was murdered in 2365, Quark met Odo for the first time. Over the years, the crooked bartender and the upright security chief played a never-ending adversarial game, yet they also developed an unspoken mutual affection. Then, after Starfleet took over the station, Quark planned to leave, but Sisko blackmailed him into staying, as an example to the other Promenade shopowners ("Emissary").
In "Move Along Home", after Quark was caught cheating the Wadi, he was forced by Falow to play an odd game, with Sisko, Dax, Kira, and Bashir as the pieces. Then, in "The Nagus", Quark briefly became Grand Nagus when Zek apparently died, but lost the position when Zek revealed that he was still alive.
Quark let a gang led by a disgruntled Trill named Verad onto the station to take over, but was later instrumental in neutralizing them ("Invasive Procedures"); and he was later threatened by a former partner named Fallit Kot ("Melora"). While trying to secure a deal with the Dosi on the behalf of Grand Nagus Zek, Quark discovered that his assistant Pel was a female Ferengi disguised as a male. Pel was in love with him, but Quark couldn't bring himself to defy Ferengi custom for her ("Rules of Acquisition"). Quark was incensed when Martus opened a gambling club on the Promenade, but gloated when it failed; he also arranged a charity racquetball match between Bashir and O'Brien ("Rivals").
In "Profit and Loss", Natima returned to the station with Rekelen and Hogue, and Quark offered to help them escape the Cardassian military in exchange for Natima staying with him. However, she ultimately chose to leave with her students.
After inviting himself along on a trip to the Gamma Quadrant with Sisko, Jake, and Nog, Quark was captured along with Sisko by the Jem'Hadar ("The Jem'Hadar"). He later was included in the mission to locate the Founders because of his connection to the Karemma ("The Search, Part I"). Then Quark was forced by Grilka, a Klingon, to marry her after he claimed to have killed her husband. He managed to save her house, whereupon Grilka granted him a divorce ("The House of Quark"). In "Prophet Motive", Quark was concerned for Zek's sanity when the Grand Nagus turned into a philanthropist; eventually, he used an Orb to meet with the Prophets and convinced them to restore Zek's greed.
In "Family Business", when his mother Ishka was caught by the FCA making a profit for herself, Quark was obliged to go to Ferenginar to get her to confess and make restitution. They finally compromised, thanks to Rom.
Quark was not happy when Nog announced his intention to enter Starfleet, and went so far as to sabotage Nog's spatial orientation test for the Academy ("Facets"). However, he finally bowed to the inevitable. In "Little Green Men", when his cousin Gaila finally sent him the ship he had promised as repayment for a loan, Quark took Nog to Earth in it, piloted by Rom, and intending to smuggle kemacite on the way back. Due to sabotage, the ship time-warped to 1947 Earth (Roswell, New Mexico), where Quark dreamed of ruling Earth with advanced technology, until forced to return and leave the timeline intact.
Quark went along on the Defiant to negotiate with the Karemma when the Jem'Hadar attacked; he and Minister Hanok managed to defuse an unexploded torpedo lodged in the ship's hull ("Starship Down"). Back on the station, Quark was incredulous, then desperate, when Rom formed and led a union to improve working conditions in the bar. He ended up agreeing to secretly meet Rom's demands in exchange for the union being disbanded ("Bar Association").
In "Body Parts", convinced he was dying, Quark put his remains on the Ferengi futures exchange. Then he learned he had been misdiagnosed, but not before his remains had been bought by Brunt, who demanded that Quark make good on the deal. Quark finally broke the contract, and Brunt confiscated his assets, declaring him an outcast in Ferengi society. The bar was restocked and refurnished by DS9 personnel.
Quark made the best of this setback. When Grilka returned to the station, he became determined to win her back, and did so, for a one or two-night stand at least, with the help of Worf and Dax ("Looking for Par'Mach in All the Wrong Places"). Quark was later stranded with Odo on a hostile planet, and they were forced to depend on each other to survive by carrying a runabout subspace transmitter up a mountain together ("The Ascent").
Sinking deeper and deeper into financial ruin, Quark was rescued from debt by Cousin Gaila, who brought him into his partnership with a dangerous weapons dealer named Hagath. However, Quark found himself morally squeamish when it came to selling weapons of mass destruction, and eventually double-crossed his way out of it ("Business As Usual"). Later, Quark's FCA business license was restored by Brunt in exchange for breaking up the romance between Zek and Ishka. Quark eventually set things right again, but retained his license, as Brunt had decided he wanted to be able to keep an eye on him ("Ferengi Love Songs").
Quark remained on the station when the Dominion and Cardassia took over ("Call to Arms"), and played a small but substantial part in saving the Alpha Quadrant. He got Damar drunk and learned of the plan to destroy the minefield, and passed it on to the New Resistance ("Behind the Lines"); and with Ziyal, he freed Rom, Kira, Leeta, and Jake from their holding cell ("Favor the Bold"/"Sacrifice of Angels").
In "The Magnificent Ferengi", when his mother was captured by the Dominion, Quark put together a rescue team, in hopes of proving that Ferengi could be as heroic as anyone else. Things didn't go quite as planned, but in the end he and his team were able to save Ishka. Not long afterwards, in "Who Mourns for Morn?", when Morn was reported dead, Quark learned he had been designated Morn's sole heir, but had to compete with Morn's former partners until eventually Morn turned up alive. And in "Profit and Lace", Quark became involved in Zek's plan to regain his office as Grand Nagus; when Ishka suffered a heart attack before an important meeting with Nilva, Quark underwent a sex change to take her place. Despite complications, the ruse succeeded, and Quark was restored to maleness. Then, in "The Sound of Her Voice", in order to distract Odo from a smuggling deal, Quark suggested that Odo romance Kira in a holosuite for their one-month anniversary; a ploy which proved successful, though Quark was unaware that Odo had actually let him "win" this one.
Quark was sent by Zek on a "fact-finding mission", on the Defiant's supply run to the front lines on AR-558 ("The Siege of AR-558"). When the mirror-universe Ezri crossed over with the news that Zek was being held captive in the other universe, Quark and Rom obtained a cloaking device to buy his freedom, and accompanied her back. They were captured first by the rebels, then by the Alliance, but eventually were able to return to our universe with Zek ("The Emperor's New Cloak").
Finally, in "The Dogs of War", due to a garbled subspace message, Quark thought that he was going to be named Zek's successor as Grand Nagus. He planned to undo all of Zek's social reforms, and sold the bar to Rom. However, when Zek arrived, it turned out that Rom was to be the actual new Grand Nagus. Rom returned the bar to Quark, who declared that it would be the last remnant of the true Ferenginar. Quark was one of the five regulars remaining on the station at the end of the series ("What You Leave Behind").