The pedestrian was struck by southbound train No. 314 around 7:40 a.m. south of the Broadway station, located at 1190 California Drive, according to Caltrain spokeswoman Jayme Ackemann.
Ackemann said as of 10 a.m. there was a backlog of trains that had been single-tracking around the incident for more than an hour.
Tracks in both directions reopened around 9:50 a.m., but passengers should expect delays of up to more than an hour, Ackemann said.
Regular service is expected to resume around noon.
Buses took customers around the scene of the fatality until about 8:30 a.m., according to Ackemann.