In all three victims suffered stab wound in the incident.
Two other victims are a 19 year old man from Oakland and a 16 year old girl. They both had to have surgery on their wounds, but are expected to recover.
Sheriff's deputies responded to a report of multiple stabbings at the station at about 10:25 p.m. Saturday.
When police arrived, they found the victims but no suspects.
It's not clear what motivated the fight.
Arriving deputies learned that three people were stabbed on the light rail platform during a fight between two groups of passengers, according to the sheriff's office.
All three victims were transported to a hospital.
The sheriff's office is investigating the stabbing and encourages anyone with information to contact Detective Sgt. Herman Leon or Detective Sgt. Ryan Elder at 408-808-4500. Callers wishing to remain anonymous can call the tip line at 408-808-4431.