Lively was spotted with a noticeable baby bump while on the set of her upcoming film "The Rhythm Section."
The couple has been married since 2012 and are already parents to three daughters: James, 7, Inez, 5, and Betty, 2.
Neither Lively nor Reynolds have publicly commented on the pregnancy, but sources close to them confirm the happy news.
Fans and followers are eagerly anticipating any updates from the notoriously private couple.
The Hollywood power duo has been open about their desire for a big family, with Lively previously stating that she wants "a lot of kids."
The two have also made headlines for their playful social media banter and strong relationship, with Reynolds declaring his love for Lively in a sweet birthday message earlier this year.
Their growing family only adds to the already solid foundation of their strong marriage. Congratulations to the happy couple!
This will be the fourth child for Reynolds and the second for lively, who also has a older sister from Ryan's first marriage.
This news comes after a sweet anniversary message from Ryan to Blake on Instagram, declaring his love for "the most vibrant, hilarious, fearless person" he's ever met.
In addition to their growing family, Blake and Ryan have also proven themselves as successful business owners and their Preserve website curates products from artisans across the country, promoting a lifestyle of community and sustainability.
Their love for each other and passion for entrepreneurship make them a power couple to be reckoned with. We can't wait to see what they do next.
No word yet on the sex or due date of the baby, but we can't wait to see how their family continues to grow and thrive.
Until then, we'll just have to settle for the adorable moments shared by Blake and Ryan on social media.
From matching Halloween costumes to sweet anniversary tributes, it's clear that these two are head over heels in love with each other.
We wish them all the best in their new journey as parents-to-be!
We can't wait to see the adorable additions to their family. Congratulations to the happy couple!
Contributed by Jasmine Sophie