The prestigious event will be known as the Betfred World Snooker Championship until at least 2017.
This year's tournament will run from April 18 to May 4 at the famous Crucible Theatre in Sheffield, with the top 16 seeds joined by 16 qualifiers to chase the £300,000 top prize.
It is one of the greatest events in sport, and last year reached an astonishing audience of over 330 million viewers worldwide, televised live by 12 broadcasters in 80 different countries.
Betfred previously sponsored the tournament from 2009 to 2012.
World Snooker Chairman Barry Hearn said: "We are thrilled to welcome back Betfred as title sponsor of our blue riband tournament and we look forward to working closely with their team on delivering another top class event.
"We recently announced that we are staying at the Crucible until 2017, so this agreement with Betfred fits perfectly and gives us a firm foundation to keep growing the event in the coming years.
"The World Championship has a rich history dating back to 1927 and the international audience we are now reaching is extraordinary. Last year's figure of over 330 million, in our key markets in the UK, Europe and China alone, was up 30 per cent on the previous year. That shows the extent to which we are developing as a global sport.
"It is building up to be a sensational tournament, with so many of the top players in form, and an array of young talents coming through. The whole event is virtually sold out, and those lucky enough to have a seat inside the Crucible are going to see something special."
Betfred boss Fred Done said: "I'm absolutely delighted to be once again sponsoring the World Snooker Championship. It's the pinnacle of the game and one of the key sporting events of the year. I'm really looking forward to be back at the Crucible which I regard as the home of snooker."
Many sessions are sold out, but for the latest ticket availability call 0844 65 65 147 or visit sheffieldtheatres.co.uk
The qualifying rounds run from April 8 to 15 at Ponds Forge International Sports Centre in Sheffield. For tickets see www.sivtickets.com or call 0114 2233777
Ball by ball scoring and results from tournaments