The 20-year-old, making her first foray into the English game with her move to City, joins from Toppserien outfit Rosenborg having scored 17 goals in 35 appearances for the club since joining them in 2020.
An exciting young player, Blakstad has put pen to paper on a two-and-a-half-year contract at the Academy Stadium and will wear the number 41 shirt.
Speaking about her move, she said: “It’s amazing to be a Manchester City player and I can’t wait to get started.
“Everybody has been amazing so far, and I’m so excited to meet my teammates. At this point in my career, it’s important to take a new step to develop myself further and I believe this is the best place for me to do that.
“You only have to look at the club – the facilities, the staff and the players all have incredible dedication to achieve something big and I really want to be a part of that.”
Formerly of Ottestad’s youth set-up, Blakstad turned professional with them in 2018 before moving to FL Fart later on that year.
Spending a season in Vang, her exploits caught the eye of Rosenborg 18 months ago - a team who have qualified for the UEFA Women’s Champions League for the past two seasons.
Also a full international with Norway and a versatile talent capable of playing in a variety of positions, she represented her homeland at U15, U16, U17, U19 and U23 level before being handed her debut for the senior side against Wales in October 2020.
Head Coach Gareth Taylor added: “We’re delighted to welcome Julie to Manchester City.
“At just 20 years old, she’s already proven what a talent she is for both club and country and she’s a player who will fit perfectly into our squad and ethos here at City.
“We’re very much looking forward to working with her over the coming years – she is an incredibly ambitious young player and we’re excited to help her develop and grow here in England.”