The 33-year-old actress starred as Sergeant Georgie Lane in four series of the BBC drama.
Our Girl creator Tony Grounds told RadioTimes.com: “With the finale of series four showing Georgie ready to move on with her life, it feels like the right time for us to do the same.”
Despite this, Tony admitted he’d be keen to reunite with Michelle at some stage in the future.
He explained: “Michelle and I are keen to continue our working relationship and, who knows, maybe we’ll catch up with Georgie in the future.
Maybe we’ll catch up with Georgie in the future
“I wanted to say a big thank you to the fans of the show, it’s been a joy to write.”
Piers Wenger, the controller of BBC Drama, added: “We are very proud of Our Girl and would like to thank Tony Grounds, Michelle Keegan and the fantastic cast and crew for all their hard work on the show.”
Michelle Keegan’s Our Girl departure
Michelle quit Our Girl after series four of the drama, revealing she was keen to “explore other opportunities” in her career.
However, the former Coronation Street actress admitted walking away from the show was a “really difficult decision” to walk away.
Michelle shared: “I just felt like I wanted to explore other opportunities.
“I’ve been doing it for four years now and I absolutely love the show, I really do and I love playing the character.”
Following her exit, Michelle revealed she would be open to returning to the BBC series.
The actress told Digital Spy: “I can’t say what’s going to happen in the future and now because it’s been on screen and Georgie hasn’t been killed.
“I can now say the door has been left open for Georgie to return. Great for me because I absolutely love the show and it’s such a special show to be a part of.”
Former EastEnders star Jacqueline Jossa was previously rumoured to replace Michelle.
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