Planet: Andoria. Humanoid Federation members are blue-skinned in appearance, with bilateral antennae that reflect their emotional state, and characteristically white hair. Andorians are self-described as a violent and warlike species, although they do have great affinity for family. No members of this Federation race were aboard the U.S.S. Enterprise NCC-1701-D when Data's offspring, Lal, was "born." Lal rejected an Andorian female as one of four final choices for a racial type, instead opting to become a human female. Apparently, according to Data on stardate 43657.0, Andorians engage in group marriages of four as a rule. However, most of what is known about this race is scattered.

This Federation member-race was the subject of some kind of gender-swapping joke by Quark that Morn was slow to catch; the punchline was "and the Andorian says, 'Your brother? I thought it was your wife!'" Andoria is among the many planets providing a registry home to numerous ships that use Deep Space Nine. Their variety of silk is prized for its softness. Andorian jewelry is highly collectible and is not usually available on Deep Space Nine — one of Quark's would-be expanded sales items by inter-station monitor. Historically, the first Vulcan-Andorian contact was encouraging, but the Vulcans felt the Andorians soon showed a duplicitous side in honoring only the self-beneficial agreements. The overall level of Andorian technology--including propulsion, weapons and sensors—is more advanced than Earth's in 2153. The military, if not society in general, is fully integrated to both males and females well before Federation membership. If Talas is any indication, Andorian women may use blue lipstick and eye shadow toned darker than their skin color. Like humans, natives show a tendency of monodexterity to either right or left. A celebratory drink of beverages, including those alcoholic, is a custom among Andorians as well as humans. Andorian ale is a favorite.

Andorian renegades in the Triangular system , it is said, once embarrassed a Starfleet admiral's supposed search when they hid their ship by dismantling it. An Andorian was present at Risa when Captain Picard vacationed there on stardate 43745.2, and also an Andorian group bid for Tellurian spices offered by Kivas Fajo on stardate 43872.2. Chirurgeon Ghee P'trell, an Andorian, was nominated for the Carrington Award in 2371.