Molly O'Brien
- Full Name: Molly O'Brien
- Born: February 27, 2368; USS Enterprise (TNG: "Disaster")
- Species: Human
- Gender: Female
- Father: Miles O'Brien
- Mother: Keiko O'Brien
- Brother: Kirayoshi O'Brien
- February 27, 2368: Resident; USS Enterprise (TNG: "Disaster", et al.)
- May 2369: Resident; Deep Space 9 (DS9: "Emissary", et al.)
- Early January 2376: Resident; San Francisco, United States of America, Earth (DS9: "What You Leave Behind..."; SCE Short Story: "Aftermath")