Lucy, who quit TOWIE at the end of the last series, is currently in Las Vegas on holiday and posted the snap of her hand on Twitter, saying: "Oops!!!! #whathappensinvegas."
The giant ring has a square canary diamond in the middle, although whether it is an actual diamond is unclear.
Fans were quick to comment on Lucy's picture, with one saying: "Is she engaged?" Another added: "U think this is for real?"
However, other followers weren't convinced: "That's not her hand!" one wrote. One even went as far as to say: "Attention seeking really isn't attractive."
Reality star Lucy flew out to Las Vegas last week for a hen party and it's clear that she doesn't want to come home!
On the weekend, Lucy even found herself brushing shoulders with US rapper Ne-Yo, who was performing in the Wynn hotel on Friday night (28 March).
Lucy, who was wearing a bikini at the time (naturally), posed for a picture with Ne-Yo before posting it on Instagram.
"Normal day!! #vegas #HelloNeyo," she commented alongside it.
Perhaps he popped the question...?! Considering he's got two children with his girlfriend Monyetta Shaw, we think this is HIGHLY unlikely!
Do you think Lucy is really engaged? Tell us below, as the best comment from across the website each week wins £50.