Protests have been held at rail stations across the capital and the UK, following the annual fare rise.
Tickets have gone up by an average of 2.3 percent from today.
Campaigners say the increase is a "kick in the teeth" following months of disrpution to some services.
The government says the rise is part of the biggest modernisation progarmme in history, and that its balanced the cost between passengers and the tax payer.
The Mayor of London Sadiq Khan joined protestors outside Waterloo station this morning, as he launched his long-awaited "fares freeze".