The new deal extends the partnership forged between the two for the launch of BBC entertainment channel, BBC America.
The BBC World News will be the sole international news channel in Discovery's distribution portfolio.
The 24-hour service was already available in 200 other countries but until now, not in the US.
Jeff Hazell, BBC World's director of distribution and business development, said: "Discovery Communications is the market leader, committed to delivering the highest quality channels and marketing support to the US multi-channel industry.
"That experience, plus Discovery's proven track record and considerable success with the BBC brand to date, will be invaluable in the roll-out of the BBC World News channel in the US."
"US consumers are ready for this unique news service - one that provides an impartial, global perspective on domestic and world events," added Bill Goodwyn, president, affiliate sales and marketing at Discovery Networks, US.
"We look forward to working with our distribution partners to deliver this compelling content in a 24/7 channel."