A surname is a name added on to the given name of individuals, often to indicate a family or clan relationship.
Vulcan family names are nearly unpronounceable by Humans. (TOS: "Journey to Babel")
Kzinti surnames were titles added to their names over their careers. (TAS: "The Slaver Weapon")
Most Klingons were addressed by their given names, and their full names had a patronymical surname, such as "son of Mogh" or "daughter of W'mar". (TNG: "Sins of the Father"; DS9: "Sons and Daughters")
The Trill are born with family last names. Once joined, they adapt their symbiont's name as their surname. (TNG: "The Host")
Many Bajorans, who have their family names as first names, have "distorted" their names in order to more easily acclimate to Starfleet and Federation norms. (TNG: "Ensign Ro")
Members of Vilix'pran's species are addressed by the second part of their name. For example, Vilix'pran is addressed as "Pran." (DS9: "Business as Usual")
The Miradorn, seem to have a surname as a hyphenated part of their own name. Evidence of this is Ah-Kel and Ro-Kel. (DS9: "Vortex")
Charles Tucker referred to Feezal as "Mrs. Phlox," likely confusing Human custom with Denobulan customs. (ENT: "Stigma")
The Ferengi do not appear to use surnames, although they have occassionally been heard to use "son of..." or "daughter of..." in a similar fashion to the Klingons.
Last names
Societies with last name surnames include:
- Atreans (TNG: "Inheritance")
- Baneans (VOY: "Ex Post Facto")
- Betazoids (TNG: "Tin Man")
- Capellans (TOS: "Friday's Child")
- Cardassians (DS9: "Second Skin")
- Humans (TOS: "The Cage")
- Klaestron (DS9: "Dax")
- 892-IV Romans (TOS: "Bread and Circuses")
- Tanugans (TNG: "A Matter of Perspective")
- Trill (DS9: "Equilibrium" see below)
- Voth (VOY: "Distant Origin")
Societies where individuals were addressed by their second name include:
- Andorians (DS9: "Prophet Motive")
- Angosians (TNG: "The Hunted")
- Argrathi (DS9: "Hard Time")
- Arkonians (ENT: "Dawn")
- Bolians (TNG: "Allegiance")
- Catullans (TOS: "The Way to Eden")
- Delb II natives (TNG: "The Drumhead")
- El-Aurians (DS9: "Rivals")
- Enarans (VOY: "Remember")
- Ennis (DS9: "Battle Lines")
- Enolians (ENT: "Canamar")
- Farians (DS9: "Prodigal Daughter")
- Ferengi (TNG: "The Perfect Mate")
- Haakonians (VOY: "Jetrel")
- Haliians (TNG: "Aquiel")
- Haven natives (TNG: "Haven")
- Idanians (DS9: "A Simple Investigation")
- Iotians (TOS: "A Piece of the Action")
- Kelemane's species (VOY: "Blink of an Eye")
- Klingons (VOY: "Year of Hell" see below)
- Kobliad (DS9: "The Passenger")
- Ktarians (TNG: "The Game")
- Lumerians (TNG: "Man of the People")
- Malcorians (TNG: "First Contact")
- Makull's species (VOY: "Time and Again")
- Markalians (DS9: "Hippocratic Oath")
- Melthusians (TNG: "Night Terrors")
- Meridians (DS9: "Meridian")
- Mizarians (TNG: "Allegiance")
- Pandronians (TAS: "Bem")
- Peliar Zel natives (TNG: "The Host")
- Promellians (TNG: "Booby Trap")
- Reegrunions (DS9: "Sanctuary")
- Romulans (Star Trek V: The Final Frontier)
- Rutians (TNG: "The High Ground")
- Sarpeidon natives (TOS: "All Our Yesterdays")
- Sikarians (VOY: "Prime Factors")
- Tagrans (TNG: "True Q")
- Takret (ENT: "The Catwalk")
- Tygarians (DS9: "The Homecoming")
- V'radians (ENT: "Rajiin")
- Varro (VOY: "The Disease")
- Ventaxians (TNG: "Devil's Due")
- Vhnori (VOY: "Emanations")
- Vidiians (VOY: "Lifesigns")
- Xepolites (DS9: "The Maquis, Part II")
- Xindi-Aquatics (ENT: "The Council")
- Xindi-Arboreals (ENT: "The Shipment")
- Yridians (TNG: "Birthright, Part I")
- Zakdorn (TNG: "Peak Performance")
- Zibalians (TNG: "The Most Toys")
First names
Societies with first name surnames include:
- Bajorans (TNG: "Ensign Ro")
- Humans (TOS: "Space Seed")
- Retellians (ENT: "Precious Cargo")
- Vulcans (TOS: "This Side of Paradise")