Daly says the surgery on his right elbow is scheduled for Thursday.
He says doctors have told him he could start rehabilitation in early September and could return to golf in the late autumn.
Daly says he has been playing with a torn tendon since May.
He says he hit a root chipping out of the rough on the 12th hole at The Greenbrier Classic on Thursday.
The surgery means Daly will miss the only two majors for which he is eligible - the British Open and the PGA Championship because he is a past champion.
He is being replaced in the British Open by Stephen Gallacher of Scotland.