The two say "no lying or cheating or fighting" led to their separation.
Brandon, son of Caitlyn Jenner and brother to Brody Jenner, and his now-estranged wife confirmed the split in a lengthy Instagram post shared to both of their pages.
"It is with love in our hearts that we feel it's time to share some personal news with you all," they wrote in the joint statement. "After celebrating fourteen beautiful years together, we have lovingly come to a decision to end the romantic aspect of our relationship."
"We are deeply proud of the life we've cultivated together and are truly grateful for the bond of friendship we hold and cherish today," they continued. "It is stronger than ever. Even though we have chosen to separate as a couple, we still love one another very, very much and remain a major part of each other's lives - as best friends, family and loving parents to our daughter."
"There has been no lying or cheating or fighting that prompted this change, just an expansion of our individual evolution which has inspired us to support each other in a new way," the statement went on. "We are still, very much, a loving family and are bonded by a deep connection that is rooted in love."
The statement concluded: "Here we openly share our truth with you all and, respectfully, we won't be commenting further so anything that might state the contrary of this message, would, undoubtedly, be a fabrication. Thank you for your love and support and big love back to you guys!"
The two, who have appeared on "Keeping Up with the Kardashians," tied the knot on May 31, 2012 and welcomed their only child, daughter Eva James, in 2015.