Blue-skinned people with antennae, founding members of the Federation.
The Andorians come from Andoria, an icy moon circling a gas giant, and their blue skin, white hair and mobile antennae make them one of the most recognisable peoples in Starfleet. Their bodies are well suited to cold and harsh conditions, and the antennae act as sensitive organs that aid balance and perception.
Andorian society prizes honour, loyalty and martial skill, and a long tradition of clan rivalry gave them a reputation as fierce warriors. Their culture places great weight on personal bonds, and their family customs famously involve groups of several partners.
Their relationship with the Vulcans was long strained by suspicion and border disputes, a tension explored in Enterprise through Commander Shran of the Imperial Guard, who clashes with Captain Archer before becoming one of his closest allies. Andoria later joined Earth, Vulcan and Tellar as a founding member of the United Federation of Planets, and Andorians have served in Starfleet ever since.