The President also commended the spirit of statesmanship displayed by the outgoing President of the country, Alhaji Yahya Jammeh, who conceded defeat.
Buhari's congratulatory message was made known in a statement issued on Saturday, December 3, by his Special Adviser on Media and Publicity, Mr. Femi Adesina.
The President also commended outgoing President of the country, Alhaji Yahya Jammeh, for conceding defeat.
He described the gesture as uncommon and crucial in calming fears of unrest in the West African nation.
Buhari, however, enjoined President-elect Barrow to be magnanimous in victory.
"President Buhari said he looks forward to a smooth transition of power and working with the incoming President of The Gambia to deepen existing cordial relations between both countries," the statement added.
Barrow, a London security guard, defeated Jammeh in the December 1 Presidential election in the country.
Jammeh has ruled The Gambia for 22 years.