The eight-day walk, arranged to raise funds for those affected by the 30-year war in Sri Lanka, begins at Killinochchi on November 1 and is due to end at Seenigama.
"It's going to be like nothing I have ever attempted before and it's going to be my most demanding," the 57-year-old Botham told a news conference on Thursday.
"I have really strong connections with Sri Lanka and I know if I can raise a lot of money it is going to do so much good for young people here. I am determined to make a success of it."
Dubbed 'Beefy's Big Sri Lanka Walk', it will raise funds for projects supported by the Laureus Sports Foundation for Goodness.
Each day Botham will be joined by cricketers such as Shane Warne, Michael Vaughan, Sourav Ganguly, Muttiah Muralitharan, Kumar Sangakkara and Mahela Jayawardene.
Botham has been walking for charity since 1985 when he first pledged to raise millions of pounds to help people suffering from blood cancers.
He visited Sri Lanka in 2005 soon after the Asian tsunami and played a key role in the establishment of the Foundation for Goodness project.
Botham was back in the country in 2009 to oversee the launch of a sports centre in the southern town of Seenigama which was hit by the tsunami.
In 2011 he made another visit for the opening of a similar sports complex in the north of Sri Lanka.
Botham is one of the greatest cricketing all-rounders of all time. He won 102 test caps, hitting 14 centuries and taking 383 wickets.
(Editing by Tony Jimenez)
