Samantha and Mark are the parents of children Benjamin, 19, and Lili Rose, 15, while she is also the stepmother of Mark’s son Michael, 25, from a previous relationship.
She said OK! magazine: “Our family home is quite large and we happily coexist. There is no rush to change things
“But now is a good time to be honest and admit that we’re not together anymore. ”
Mark is also an actor and they met on the set of crime drama Liverpool 1 in 1998 before they were married in 2009.
He is best known for his role in Emmerdale, playing DI Mark Malone earlier this year.
Samantha revealed that they parted ways two years ago but have decided to continue living together and they remain “best friends”.
She told the magazine, “We decided that we didn’t want to stay in a romantic relationship, but we liked the way we lived.
“We have this beautiful house and we spend a lot of time away from each other. We are still a family and we love and adore each other.
“He’s always been the best relationship of my life and I think he would say the same about me.
“So we sat down with the kids and explained to them that we weren’t going to be in a romantic relationship anymore, but that we would still be best friends.
“We have lived happily together ever since. It’s weird, but it’s probably the best years we’ve had as a family. “
She goes on to attribute the separation to the time they had to spend away from each other while working and a breakdown in communication.
News of the secret split comes just days after Samantha’s onscreen sister Rita Simons, who played Roxi Mitchell, also ended her marriage and kept him silent.
Rita separated from her husband, hairstylist Theo Silverston, almost two years ago.
The two actresses left the soap opera at the same time in 2017 as their characters drowned in a heartbreaking New Years episode.