"You've made me the luckiest girl in the world," Peltz wrote alongside her own post of the photograph. "I can't wait to spend the rest of my life by your side. your love is the most precious gift. I love you so so much baby and thank you harper for this pic."
But it seems like her stunning 5-carat diamond engagement ring, believed to cost around $450,000 AUD, wasn't the only gift she received on the day.
Seen in the image, Peltz wore a stunning, flowy lemon-hued gown to announce her exciting news.
In a surprise to no one, the dress was designed by Victoria Beckham and forms part of the former Spice Girls’ SS20 collection.
The 'Asymmetric Ruffled Silk-Georgette Midi Dress' has since sold out on NET-A-PORTER's Australian website, with only Canada able to access the dress.
"Fresh colours and fluid silhouettes in motion," the fashion designer described the dress on her Instagram.
"It's a sunny Sunday," another post reads of the same dress.
Sending her congratulations to the newly-engaged couple, Victoria Beckham shared the post on her own Instagram account, along with the caption:
"The MOST exciting news!! We could not be happier that @brooklynbeckham and @nicolaannepeltz are getting married! Wishing you so much love and a lifetime of happiness. We all love you both so much."
Peltz commented on the star’s post: "I love you so so much victoria i'm the luckiest girl". And that she is.
We're placing our bets now, that the actress will choose to wear a Victoria Beckham original for her big day. However, only time will tell.