In the snap, the "Off The Vine" host recreated the iconic drawing scene from the 1997 film. To reenact the scene, Bristowe, as Rose, lounged on a white couch with a beige sheet tastefully covering her nude body.
To complete the look, the 37-year-old rocked a red curly wig, gold bangles and a bright blue pendant.
Her fiancée, Jason Tartick, took on the character of Jack. He wore a white button-up with the sleeves rolled past his elbows, hard at work on a drawing of Bristowe.
In the film, Rose tells Jack, to "draw me like one of your French girls." Clearly, the duo got the scene spot-on.
In the caption, the reality star paid homage to the film while also referring to her fiancée.
"I believe you are blushing Mr Tartick..." she penned alongside the hashtag "Titanic."
In the comments, fans went wild over the couple's "genius" costume.
"Oh wow, this is absolutely genius and I cannot get over this!" commented a follower.
"This just took me right back! The necklace, the pose, the Leo! Perfection. 10/10," penned a fan, referring to Leonardo DiCaprio, who played Jack in the film.
"Amazing! This is so so so good!" shared someone else.
"You guys totally nailed it," added another. "Spot on."
However, Bristowe wasn't the only celebrity getting dressed up for Halloween.
This year, superheroes such as Mystique and Storm, as well as fairytale characters like Rapunzel and Ariel were popular choices for costumes.
Yahoo Canada has gathered a list of some of the best celebrity Halloween costumes from 2022, which you can check out here.