The ITV Player app will automatically download to Now TV boxes as part of a phased rollout, enabling users to access catch-up content from ITV, ITV2, ITV3, ITV4 and CITV from the last 30 days on their main TV.
ITV will also make the 34 World Cup football matches it is covering available through the Player app.
The addition of ITV Player follows the integration of BBC iPlayer, 4oD and Demand 5 to the Now TV box.
BSkyB said it would also roll out a new software update to the device within the next month, creating a refreshed home-page screen and a new look and feel. The refreshed version will also include the BBC Sport app.
“A key part of our strategy is to make our content available to viewers on multiple devices, and we are delighted to offer Now TV customers the chance to catch up on their favourite ITV programmes with the Now TV box,” said Martin Goswami, director of pay and distribution at ITV.