Aria T'Loak, also known as "the Pirate Queen", is an asari organized crime boss who serves as the de facto ruler of Omega Station, the unofficial capitol of the outlaw Terminus Systems. She owns the Afterlife Club, which serves as the station's central hub, and maintains her hold via a strong intelligence network and her ability to read people. Her first chronological appearance is in Mass Effect: Incursion, an 8-page prequel comic to Mass Effect 2. She then makes a cameo in Mass Effect: Redemption, briefly assisting Liara's search for the missing Shepard. In Mass Effect 2, Aria provides Shepard with information on Omega, and can hire Shepard to protect one of her advisors from assassins. In Mass Effect: Retribution, Aria serves as a supporting antagonist. Cerberus defector Paul Grayson is working for her, and also romantically involved with her daughter, Liselle. Aria is manipulated into helping Cerberus track down Grayson (who she is duped into believing responsible for her daughter's murder), and to get revenge on a turian strike force that seized control of key Cerberus facilities. She kidnaps Kahlee Sanders and David Anderson in an attempt to use them as bait to entrap Grayson. This backfires, however, as Grayson has become indoctrinated by the Reapers, and his upgrades enable him to decimate Aria's forces. Though angered by the loss of her men, Aria grudgingly continues a business alliance with the Illusive Man.

Aria is the protagonist of Mass Effect: Invasion, which finds Omega under siege by Reaper constructs called Adjutants. Aria briefly joins forces with Cerberus to fight the Adjutants, but is betrayed and ultimately forced to leave Omega under Cerberus control.

In Mass Effect 3, Aria is on the Citadel, and occupies the nightclub Purgatory. She makes no secret that she hates being confined to the Citadel and plans to retake Omega, but also realizes that such plans are meaningless if the Reapers win. She agrees to assemble a team of mercenaries to assist with the war effort, and instructs Shepard to convince the leaders of the Blue Suns, Eclipse, and Blood Pack to flock under her banner. It is unknown as to whether she survives the end of the game.

Aria returns in the game's "Omega" DLC where she enlists the aid of Commander Shepard on a desperate mission to regain control of the Omega station from the ironclad rule of a large Cerberus army, led by General Oleg Petrovsky, the Illusive Man's most brilliant military commander, and a tactical genius who managed to force Aria to abandon her rule of the station not long before the Reaper Invasion began, in order to gain access and control of the Omega 4 Relay and the remains of the Collector Base from beyond.

Aria is voiced by Carrie-Anne Moss.