The glamour model-turned-businesswoman has dated the hunk since they met at Sir Elton John's Oscars party in Los Angeles last year (11), and they became engaged in April (12).
They have now decided to go their separate ways, but Price is adamant they remain the ""best of friends"".
Announcing the split on her website, she writes, ""Leo and I have had a lovely fun time for a couple of years, we will always feel deep affection for each other, but sometimes relationships just run their course.
""Pressures of work on different continents, natural demands of family ties, and careers, have meant we have spent a huge amount of time apart even when we were in the same country. This meant it was difficult for the relationship to move forward.
""Accordingly we've mutually decided to call it a day, but we really wish each other nothing but the very best and will remain best of friends. Whoever he eventually settles down with will be a very lucky girl."
Price was previously married to Australian singer Peter Andre and cage fighter Alex Reid.