They said in a statement they made their decision after "extended counseling" and pointed out there was no extramarital affair, The Denver Post reported.
Hickenlooper will live in the Governor's Mansion but will spend time with their 10-year-old son Teddy at their Denver-area home, the newspaper said.
Hickenlooper, touted by some as a possible presidential candidate in 2016, and Thorpe, a journalist and author, said their separation -- after 10 years of marriage -- is "mutual and amicable," and they intend to "continue functioning as a family that spends a great deal of time together."
"In fact, we will embark on our annual family vacation together this week, share meals often and plan to spend holidays together," they said in their statement. "You can continue to expect to see both of us out in the community -- sometimes together, sometimes solo. Please feel free to include both of us in social gatherings as we will not find it awkward."