Reynolds shared the photo on social media while also speaking out about climate policy.
Ryan Reynolds and Blake Lively's relationship has for a long time been seen as "couple goals" by the general public.
Sharing both a close relationship and wicked sense of humour with one another, their tweets and social media posts have delighted their fans for years. Ryan's latest post is no different.
For the first time, the star has shared a photo of their new arrival and may have also given away the gender of the baby in the caption.
In the photo, the couple can be seen gazing lovingly into each other's eyes with their bundle of joy nestled between them.
The Deadpool star captioned the post:
"I love B.C. I want my daughters to experience the same natural playground I grew up in. On Oct. 21, the candidate you vote for will SHAPE CLIMATE POLICY. I’m proud of the climate progress made the last 4 years. Click http://Elections.ca for voting info. #Capilano."
Many followers have taken this to mean that the couple have had another girl - a welcome addition to their family of two other daughters, James, four, and Inez, two.
Congratulations to the happy couple!