The popstar, who jetted into LA over the weekend with long black hair extensions, has now unveiled striking blue locks!
Jessie showed off her new hairdo in a series of Instagram snaps yesterday and she looked pretty fierce.
Sporting dark berry lipstick, a black beanie hat and round framed sunglasses, Jessie pulled off a series of funny facial expressions.
"Keep em guessing! Studioooo time," she told fans.
Jessie, who headed out to the States to work on the US version of her album Alive, later added: "Blue hair don't care."
Just one week ago, Jessie debuted a black bob wig at the Brit Awards launch party, before putting in hair extensions for her trip to the States days later.
This is now Jessie's third hair transformation in the space of seven days - she really is keeping us on our toes!
Apart from spending time in the recording studio, Jessie has been taking advantage of the open parks and stunning scenery by going for a morning run at the Runyon Canyon Park near Santa Monica Mountains.
She told fans on Instagram: "LA makes you wanna keep strong and be healthy."
What do you think of Jessie's new hair? Let us know by commenting below as the best comment across the site each week wins £50!
Watch Jessie's music video for 'It's My Party' below: