The Bad Boy Records boss, 49, split from Cassie, 32, in October (18) after dating on and off for 11 years, and she soon moved on with personal trainer Alex Fine.
The R&B singer went public with the new romance in December, and on Wednesday, June 12, she took to Instagram to announce they are expecting a baby girl.
"Can't wait to meet our baby girl. Love You Always & Forever," the "Me & U" star wrote alongside a slideshow of pictures of herself and her boyfriend.
Now Diddy has offered his words of support to his former partner by sharing a photo of the parents-to-be on his Instagram page.
"Congratulations @Cassie and Alex," he captioned the image. "I wish you all nothing but love and happiness. God bless."
DJ Diplo, producer Dallas Austin, and even embattled hip-hop mogul Russell Simmons also commended Diddy for choosing to accept the news with love.