The deal, thought to be worth around £50m a year, will mean England's home matches are broadcast on ITV and their away fixtures on the BBC.
France, Scotland and Wales home games will remain on the BBC, with ITV taking England, Ireland and Italy's home fixtures - the broadcasters will swap teams for away games.
The sharing of a tournament the BBC has held exclusive rights to for 12 years comes after it lost out on rights to future Olympic Games.
ITV adds the February/March tournament to its exclusive Rugby World Cup coverage.
Director of sport Niall Sloane commented:
As ITV prepares to bring viewers exclusive, free-to-air live coverage of the Rugby World Cup later this year, we're delighted to be strengthening our ties with the game by bringing audiences the first-class, live action and unique atmosphere of the RBS 6 Nations from next year.
Sky is believed to have entered the bidding, but did not match the combined £300m offer put forward by the two terrestrial stations.
Labour shadow sports minister Clive Efford reacted positively to the news, arguing: "It would be a huge mistake for another rugby competition to be put on subscription television, further limiting the exposure the sport gets, particularly to the next generation of potential rugby fans."