Nessarose, or "Nessa," sister of Elphaba the Wicked Witch of the West in the musical "Wicked"
Nessa, character from "Gavin & Stacey"
Nessa, one of the Valar ("angels") from Tolkien's Legendarium
Nessa Stein, main character of the British miniseries "The Honourable Woman"
Nessa Holt, character from TV series Las Vegas