The 65-year-old actor is a first-time grandfather.
As Alec's eldest daughter, Ireland Baldwin, 27, welcomed her first child on Thursday -- a daughter named Holland -- Hilaria took to Instagram to offer a heartfelt congratulations from their growing brood.
"All of these aunties and uncles and us grandparents are so excited that Holland is here!!!" she captioned a happily chaotic snapshot of herself and Alec with their seven younger children. "Congratulations to the mama and papa, Ireland and Andre. We love you so very much!"
For his part, Alec shared a sweet throwback image of himself holding a young Ireland on his lap.
"My first baby had her first baby," he captioned the shot. "Much love to the three of you!"
Ireland announced the happy news with a snap of the newly-minted family of three snuggling in her hospital bed.
In addition to Ireland, Alec is a proud dad to Carmen, 9, Rafael, 7, Leonardo, 6, Romeo, 4, Eduardo, 2, Lucia, 2, and Ilaria, 8 months.