The star shared the happy news on Instagram, writing a heartfelt caption which thanked both his bride and the hundreds of people who travel abroad to watch the pair say "I do".
"Huge thank you to the incredible team that gave us the most incredible wedding we are forever indebted to you for making this day a dream come true," he wrote alongside a beautiful picture of the pair following their nuptials. "We are still floating. To all our friends and family who came, we love you and we will never forget you."
His makeup artist wife also shared her excitement on Instagram, reposting the photo from inside the reception.
“Yesterday my best friend asked me to marry him in the most romantic way, a day reliving our love,” she wrote. “We are thrilled. I wouldn’t want to do this life with anyone else. I love you baby and can’t wait to be your wife 💍 This man has showed me what true love is. What a dream come true, pinch me.”
While his on-screen love interest Ellen Pompeo, as well as his Grey's sister Stefania Spampinato didn't attend the wedding, they both commented on the post with love heart emojis.
Giacomo popped the question in 2017.
WATCH: The way he proposed is SO EXTRA!
“She said yes,” he captioned a sweet shot of the couple kissing on a balcony in Los Angeles. “I am truly one lucky guy, and I wouldn’t rather be walking down this crazy road of life with anyone else. I love you. Thank you.”
What a beautiful moment! Congratulations to the happy couple.