The actress, 42, wants to focus on her shaken marriage with fourth husband Jeremy Healy, according to TV Biz. Kensit's spokesman confirmed that she and her husband are "experiencing difficulties" and are trying to "work things out".
She will leave the BBC One soap in September when her character, ward sister Faye Byrne, is written out.
"I have had a fantastic time playing Faye but I felt it was the right time to move on," she said. "I will really miss the cast and crew, but not the long hours. It has been lots of fun but very hard work. Although it can be a tough schedule at Elstree Studios, I will be very sorry to say goodbye to the fantastic team there."
It is understood that Kensit's character will not be killed off, leaving the possibility of a return on the cards. Her final scenes are likely to air at the end of the year.