Weyoun was a Vorta diplomat and leader who served the Dominion in the 24th century. Like all Vorta, Weyoun was a clone, with which at least eight copies were known to exist, five of which were encountered by the Federation in the 2370s. During the Dominion's war with the Alpha Quadrant, Weyoun served as the Dominion representative in the Cardassian Union where he personally oversaw most aspects of the war as well as ensuring the loyalties of Cardassian leaders such as Skrain Dukat and Corat Damar.
In 2394, he travelled to Bajor to attend the Festival of Tears. After the detention of Jake Sisko Weyoun spoke to Jake to convince him to join him in denouncing the Reckoning Tablet as a fake artefact. He also offer an open dinner invitation to Jake, who said he would consider the offer.
After Jake accepted the offer Weyoun created gumbo for their dinner. When Jake revealed he was there to convince Weyoun to return the tablet to the Bajorans he was not surprised as he knew that Jake would only accept his dinner invitation if he had ulterior motives. Weyoun refused to return the tablet and got into a struggle with Jake over the tablet, which led to Jake accidentally smashing in to pieces against a wall. Before they could discuss what to do about the situation Weyoun was informed that Dukat was on the station and was creating a disturbance on the promenade.
Weyoun headed to the promenade to confront Dukat and tried to distract him so the Jem'Hadar could kill him. However, it failed as Dukat was warned of the attack by the Kosst Amojan sharing his body. Weyoun narrowly avoided been killed by Dukat by pushing Gelnon in front of him to take the brunt of a telekinetic attack. Weyoun was knocked down and concussed by Dukat trying to escape. Dukat savagely beat Weyoun and started to strangle him, but Weyoun was saved by the arrival of the Prophets' instrument and the Kosst Amojan taking control of Dukat for its confrontation with the Prophet.
Weyoun attempted to stop the Reckoning by travelling to the station's Ops centre to flood the promenade with chronitons. However, he was killed by the station's commander, Colonel Antara Eri, to prevent his interference.
Several days following his death, a new clone had been activated. This clone travelled to Bajor to oversee the investigation into the disappearance of the Bajorans and the wormhole. 
- Jake notes that Weyoun had changed little in the twenty years, which could mean that this Weyoun was a subsequent clone of Weyoun 5.