Meghan Markle, Prince Harry and Archie are heading to South Africa on September 23, before the Duke makes solo trips to Malawi, Angola and Botswana.
The couple's first tour with their son Archie Harrison kicks off on September 23 and will run until October 2.
The trio will be visiting South Africa together, while Harry will be making solo trips to Malawi, Angola and Botswana.
During a "particularly significant and poignant journey", Harry will return to Angola to see first-hand the legacy of his mother Princess Diana.
Her visit to Huambo in 1997 helped raise awareness of the threat posed by landmines to communities and livelihoods.
A statement released this afternoon reads: "This will be Their Royal Highnesses’ first official tour as a family.
"Not only will this visit serve as an opportunity for The Duke and Duchess to highlight many of the causes they have been involved with for many years, it will demonstrate a modern UK-Africa partnership in action.
"The Duke of Sussex’s love for Africa is well known; he first visited the continent at the age of thirteen and more than two decades later, the people, culture, wildlife and resilient communities continue to inspire and motivate him every day.
"As Her Majesty’s Commonwealth Youth Ambassador, The Duke now has a platform to be able to support young people across Africa in reaching their full potential."
Meghan and Harry will visit Cape Town and Johannesburg together, and the Duchess will carry out solo engagements during the trip.
The statement reads: "Through her Patronages, The Duchess will be working with organisations to promote women’s education, health, entrepreneurship and leadership.
"The Duchess of Sussex is particularly looking forward to the opportunity to learn from inspirational women in the region.
Britain's Diana, Princess of Wales in the land mine fields in Huambo in Angola
"As Patron of the Association of Commonwealth Universities, Her Royal Highness will meet female entrepreneurs, academics and community leaders, and join discussions with Southern African young women about the future of their countries."
While Meghan remains in South Africa, Harry will head to Angola on September 26 to see some of the work his mother was so passionate about.
UK Charity Halo Trust is initiating a programme of de-mining for conservation, funded by the Angolan government, which has the ambition to become landmine free by 2025.
On the following day he will visit a working de-mining field outside Dirico where he will remotely detonate a mine and meet members of the community.
The statement reads: "In a particularly significant and poignant journey, The Duke of Sussex will have the opportunity to return to Angola to see first-hand the legacy of his mother the late Diana, Princess of Wales, whose visit to Huambo in 1997 helped raise awareness of the threat posed by landmines to communities and livelihoods.
"The work of the late Princess, and commitment to this issue, changed global opinion.
"Now, more than two decades later, humanitarian de-mining work continues and the Angolan Government has made a significant financial commitment to clearing landmines from another large area important for conservation of Angola’s unique ecosystem.
"The Duke will launch this new project, operated by the HALO Trust, and will also visit Huambo to see how, what was once a dangerous area, has developed into a thriving community after being cleared of mines.
The couple will visit Cape Town during their trip
They will also spend time in Johannesburg
"There he will meet the men and women who have undertaken the dangerous and vital work of mine clearing and visit the orthopaedic centre that is treating mine victims."
On the final day of their trip the couple will meet Graça Machel, widow of the late former President Mandela. The Duke last met with Mrs Machel in South Africa in 2015.
The couple teased details of their trip on their Instagram page earlier this week, and Harry said he "can't wait" to introduce his family to the country .
Prince Harry in Nelson Mandela's office with Graca Machel his widow at the Nelson Mandela Foundation Centre of Memory on December 3, 2015
Posting on Sussex Royal, he wrote: "In just a few weeks our family will be taking its first official tour to Africa, a region of the world that over the past two decades has been a second home to me.
"Our team has helped create a meaningful programme that we’re so excited to share with you.
"On a personal note, I can’t wait to introduce my wife and son to South Africa! We’ll see all of you very soon - The Duke."
It's the couple's second big Royal Tour, the first being their trip to Australia and New Zealand at the end of last year.