Denver media reported Friday that the two-time Super Bowl winner proposed to 41-year-old Paige Green during a trip to Italy last week.
Elway told the Rocky Mountain News he was "looking forward to a long life together" with Green.
A telephone message left by The Associated Press with Elway's secretary wasn't immediately returned.
The 48-year-old Elway was previously married to Janet Elway for 18 years. They have four children.
According to The Denver Post, Elway and Green met three years ago at a golf tournament in Los Angeles.
In a recent interview, Green talked about the couple's first date.
"It either gets better or worse from there," Green told Denver Magazine. "In this case, it got good enough that I moved to Denver a year later."
Information from The Associated Press was used in this report.