The Obsidian Order was the intelligence service of the Cardassian Union, tasked with internal security, until its destruction by the Dominion in 2371. While the organization's role as an intelligence service has been taken over by the Cardassian Intelligence Bureau, many surviving Obsidian Order operatives are believed to have joined or support the True Way.
- In 2371, the Obsidian Order and the Romulan Tal Shiar use the Orias System as a staging point for an attempted attack on the Founder homeworld in the Gamma Quadrant. The attack is a failure and large numbers of ships and personnel from the two intelligence services are considered lost. The Obsidian Order is effectively wiped out.
- In 2409, True Way forces make a raid on Cardassia Prime to steal the Orb of Possibilities from an Obsidian Order facility. The Obsidian Order had maintained possession of the Orb since the Occupation of Bajor, in violation of the 2371 Bajoran/Cardassian Treaty.
- Message From Another Time II: Commander Nereda poses as an Obsidian Order agent in the 23rd Century to stop a Na'Kuhl assassin on Cardassia Prime, the assassin having intended to set off a bomb in a market which would have killed a young boy named Procal Dukat. The boy would later father the infamous Gul Dukat.