The 29-year-old - who plays resident GP Dr Al Jenkins - recently finished filming with the East-End soap and is about to embark on a charity trip to Malawi with relief and development organisation World Vision.
Speaking of his exit, Croasdell told DS: "I have worked with and befriended a lot of fantastic actors while I have been at EastEnders. I am very grateful for my time on the show and all the support shown to me to me by the wonderful viewers who have followed my storylines and been so supportive. I see it as a chapter in my ongoing work as an actor - as I am always interested in new challenges, so I am looking forward to future projects."
He is expected to make his screen exit in February.
Having grown up in Walford as a child, Al first returned to the Square in May to visit his mother and soon became the local doctor. He quickly became involved with Heather Trott's (Cheryl Fergison) pregnancy plot, before going on to have a brief dalliance with Tanya Branning (Jo Joyner). Al then served as the catalyst for Stacey Slater's (Lacey Turner) sectioning as her bipolar disorder spiralled out of control.
More recently, he has become entangled in a love triangle between Roxy Mitchell (Rita Simons) and Chelsea Fox (Tiana Benjamin).
A Walford source said: "Al's a massive support to Roxy following Archie's death at Christmas, and when he's offered a job at his father's medical practice in Cornwall, he decides to up sticks and leave the high life behind. But will he manage to convince Roxy or Chelsea to go with him? Or will he go off into the sunset alone?"
Croasdell recently revealed that he would be playing the role of James Bond in Activision's next game in the franchise.
Barbara Windsor (Peggy Mitchell), Charlie Clements (Bradley Branning) and Josie Lawrence (Manda Best) are all due to leave next year.
Executive producer Diederick Santer will also step down at the end of February to make way for incoming exec and former Hollyoaks producer Bryan Kirkwood.
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