The Gambia is rejoining the Commonwealth, almost five years after it withdrew under the rule of ousted President Yahya Jammeh who branded it a "neo-colonial institution".
The BBC reports that the occasion will be marked at the Commonwealth's headquarters in London later today.
President Adama Barrow applied for The Gambia's readmission to the body soon after he took office last January.
Mr Jammeh fled into exile, ending 22 years of authoritarian rule in the small West African state - a popular tourist destination.
The Gambia will be the fourth country to return to the Commonwealth - after South Africa, Pakistan and Fiji.
Mr Jammeh clashed with the Commonwealth over his government's poor human rights record.
Mr Barrow has sought to improve The Gambia's relationship with Western governments, and to secure much-needed funding to tackle poverty and unemployment.
