Bolt revealed the news on Instagram with a Father's Day family photo, showing a lightning bolt emoji next to each of his children's names in the caption, without stating when the twins were born.
Bennett also posted a shot of the couple posing with the twins and daughter Olympia Lightning Bolt captioned: "Happy Father's Day to my forever love! @usainbolt You are the rock of this family and the greatest daddy to our little ones. We love you world without end!"
Olympia Lightning was born in May 2020 but the name was only announced two months later.
Messages of congratulations poured in after Bolt's Instagram announcement, from fans as well as athletes -- including fellow Jamaican sprint star Shelly-Ann Fraser-Pryce, American 200m specialist Wallace Spearmon and 200m world champion Dina Asher-Smith of Britain who posted "Congratulations so adorable!"
The 34-year-old Bolt, who won eight gold medals at the 2008, 2012 and 2016 Games, will not be competing at the Covid-delayed Tokyo Olympics next month after retiring in 2017.
The fastest man in history, Bolt holds the world records for 100 metres and 200 metres. He is the only sprinter to win the 100m and 200m double at three consecutive Olympics.
Bolt, who won 23 major championship golds in a glittering career, tried to turn to professional football after his track career ended, but failed to secure a contract and retired from all sport in 2019.
"It was a good experience. I really enjoyed just being in a team and it was much different from track and field and it was fun while it lasted," he said at the time.