The petite brunette headed for a night out in the capital to celebrate the popular holiday and went for the wow factor when it came to her outfit.
Donning a flattering black dress, Lucy proved that all of those gruelling workouts she was spotted doing over the summer have certainly paid off.
She kept the rest of her costume super simple, only adding a slick of red lipstick, a pair of silver earrings and some spooky contact lenses.
And apart from the bright green contacts, Lucy admitted that the rest of her get-up wasn't exactly a terrifying Halloween look.
This morning she tweeted: "So I ended up not looking that scary last night..."
Well, she may not have looked scary but we're sure she still turned heads.
While Lucy enjoyed a spooky evening partying with her pals and getting glammed up, her ex boyfriend Spencer Matthews was pictured looking a tad more low-key at a birthday bash in Westfield shopping centre.
Spencer and Lucy split earlier this year, after the feisty brunette discovered that her beau had cheated on her.
And although she has insisted that she doesn't want another boyfriend anytime soon, Lucy has recently been seen spending a lot of time with MIC co-star (and Spencer's best friend!) Jamie Laing.
The pair even shared a kiss on this week's episode of the hit E4 show and apparently met up with each other last night!
What do you think of Lucy's Halloween costume? Let us know below, as the best comment each week wins £50!