The Aussie paired with Ethan Warren to take out second places in both the 10 metre platform and three metre springboard synchro events. He had already picked up a silver in the one metre springboard.
Mitcham's pet event is the 10 metre individual platform, in which he won gold at the Beijing Olympics.
"They say good things come in threes, it's my third silver so I will be going for a gold," Mitcham said.
His biggest threat comes in the form of England's 16-year-old diving star Tom Daley.
Mitcham is experiencing an outpouring of support in Delhi, with Indian fans holding up signs saying "Matthew Mitcham: India loves you".