Usain Bolt and partner Kasi Bennett have had twin boys named Thunder and Saint Leo, who join a family that also includes Bolt's one-year-old daughter Olympia Lightning.
The eight-time Olympic athletics champion and world record holder in the 100m and 200m announced the children's births on Instagram to mark Father's Day.
Bennett added in a separate post that the sprinter was "the rock of this family and the greatest daddy to our little ones".
However, neither Bolt nor Bennett confirmed when the twins had been born.
Earlier this year, Bolt said he valued his gold medals more than his world records.
"It's always going to be the [Olympic] gold medals," Bolt said to CNN Sport.
"I think that's what really stamped my authority on the sport, you know what I mean, I showed my dominance throughout the years.”
More recently, he said he is considering moving into coaching.
"It's something that we have talked about, but I'm not really into coaching that much, because I have no patience, you know," Bolt told Naomi Campbell.