In a post on Facebook, Sandberg announced she is set to marry marketing executive Tom Bernthal.
"Engaged!!! Tom Bernthal, you are my everything. I could not love you more," wrote Sandberg on Monday.
"You're wonderful for each other and Ia¿m so happy for both of you," Facebook CEOI Mark Zuckerberg commented on her post.
Tom is founder and CEO of a Los Angeles-based strategic consulting agency.
In 2015, Sandberg who is author of the feminist bestseller "Lean In," came into limelight after the sudden death of her husband David Goldberg at age 47.
Goldberg, who was the CEO of online polling firm SurveyMonkey, died after falling on a treadmill and striking his head in Mexico.
In 2017, Sandberg released a book about her experiences overcoming grief and adversity, titled "Option B: Facing Adversity, Building Resilience, and Finding Joy".
In a Facebook post, Sandberg said that the book focuses on how she learned to find meaning and happiness after the sudden death of her husband.
"A few weeks after my husband Dave died, I was talking to my friend Phil Deutch about a father-son activity that Dave was not here to do. We came up with a plan for someone to fill in so my son would not have to miss out. I cried, 'But I want Dave.' Phil put his arm around me and said, 'Option A is not available. So let's just kick the shit out of Option B,'" Sandberg wrote.
"Because no one's life is perfect, we all live some form of Option B," she wrote.
"It's my deepest hope that Option B will help others learn what I learned: that when life pulls you under, you can kick against the bottom, break the surface, and breathe again".
( With inputs from IANS )