It followed the birth of the couple's first child, Olympia, in June last year.
Bolt and Bennett have been an official couple for six years and their beautiful family continues to grow.
Bennett also shared the news on social media with an identical photograph.
She wrote: "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!"
The eight-time Olympic gold medallist has been retired from athletics since 2016, but turned his attention to a professional football career, which included a brief cameo with A-League team the Central Coast Mariners.
