His only challenger, Prime Minister Lionel Zinsou, conceded defeat earlier.
Mr Talon got 65% of the votes while Mr Zinsou secured 35%.
Polls took place in four other African nations over the weekend, including Congo-Brazzaville, Cape Verde, Niger and Tanzania’s Zanzibar islands where the incumbent president won.
“I feel like a soldier packing for the front. This is not a day of glory – congratulations will have to wait,” Mr Talon said, Reuters news agency reports.
President Thomas Boni Yayi is stepping down after two terms.
His decision to leave office stands in contrast to leaders in other African nations like Burundi, Rwanda and Congo-Brazzaville, which have altered their constitutions to extend presidential term limits.
Mr Talon used to be a close ally of the outgoing president, but was accused of masterminding a plot to poison him in 2012, allegations he strongly denies.
He returned from exile in France last October, after receiving a presidential pardon.
This is a turnaround from the first round vote last month when Mr Talon came slightly behind Mr Zinsou, who is Franco-Beninese and used to head France’s largest investment bank.
He was considered as “France’s candidate” by his detractors.