Public donations to the Mary’s Meals initiative Double The Love before March 1 will be matched by the UK Government up to £2 million.
The charity say more than 360,000 primary school children are out of education in the country which has high rates of malnutrition, poverty and food insecurity.
Mary’s Meals also says the average global cost is £13.90 to feed a child for a whole school year.
Bannatyne said: “When I first came across Mary’s Meals, they had just started feeding 200 children in Malawi, and now they reach more than 1.3 million children all around the world.
“I am amazed at how much they can do with even the smallest donation and having seen their work in action, I know how life-changing the meals are for the children, their families and communities.
“With the match-funding from the UK Government, every donation right now will go even further - in fact, a donation of just £13.90, when doubled by the government, will feed two hungry children for a whole year.
“It really is a great time to get involved and do something fantastic.”
The Scottish tycoon was awarded an OBE in 2004 recognising his charity work, including that with Mary’s Meals.
Any donations made over the £2 million will not be matched, but continue to go to general funds of the charity which helps feed youngsters in 17 countries across five continents.
Daniel Adams, the charity’s executive director, added: “Duncan has been a great friend to Mary’s Meals for many years and like so many people, he is inspired by the simplicity of our vision that every child receives one daily meal in their place of education.
“The work of Mary’s Meals is only possible because of the kindness of people of all ages and from all walks of life.
“Right now, with match funding from the UK government, we have this wonderful opportunity to transform the lives of many, many more hungry children in Zambia and around the world with the gift of food and education.
“Even the smallest gift will go a long way to bring joy to children and help them look with hope towards a brighter future.”