Which companions have romance options?

Here's a breakdown of who you can romance based on class (source):

Jedi Knight

• Kira Carsen (F)
• Doc (M)

Jedi Consular

• Zenith (M)
• Lt. Iresso (M)
• Tharan Cedrax (M)
• Nadia Grell (F)

Sith Inquisitor

• Andronikus Revel (M)
• Ashara Zavros (F)

Sith Warrior

• Vette (F)
• Jaesa Willsaam (F) (dark side only)
• Malavai Quinn (M)
• Lieutenant Pierce (M)

Trooper

• Aric Jorgan (M)
• Elara Dorne (F)

Smuggler

• Corso Riggs (M)
• Risha (F)
• Akavi Spaar (F)

Bounty Hunter

• Mako (F)
• Torian Caldera (M)

Imperial Agent

• Kaliyo Djannis (F)
• Vector Hyllis (M)
• Ensign Raina Temple (F)

Jedi Knight

Male

• Kira Carsen (companion)
• Ranna Tao'Ven, after completing The Face of the Enemy

Republic Trooper

Male

• Sergeant Jaxo, after meeting her again at the end of the mission on Port Raga: Optional: A Little R and R