All matches in the biggest annual rugby tournament in the northern hemisphere will remain on free to air television.
From next season the TV and online rights to the Six Nations will be shared between the BBC and ITV.
The BBC will transmit live coverage of all home matches in Scotland, Wales and France and ITV will transmit live coverage of all home matches in England, Ireland and Italy.
Both free to air broadcasters will have the rights to show highlights from the matches they do not broadcast live on their channels.
WRU Chairman and Six Nations Council member, Gareth Davies, said: “I am delighted we have been able to achieve a deal which delivers the very best for Welsh rugby.
“The deal guarantees that the games will be available on free to air channels for the next six years, whilst the financial terms of the contract deliver a significant uplift which will prove of great benefit to the game in Wales.
“We already enjoy a great relationship with both the BBC and ITV which offers us great confidence that the tournament will continue to command the level of coverage it deserves.
“We were determined to ensure a fair financial settlement, but the need to keep the games on free to air channels was also a strong motivator.
“This is great news for all our supporters and I know this is a contract which will please all our key stakeholders.”
WRU Group Chief Executive and Six Nations Council member, Roger Lewis, added: “This is great news for rugby and great news for Welsh rugby.
“Having been part of the negotiating team for the past ten months I am delighted we have achieved such a great result.”
