
Johnson has joined world number one Jason Day and four-time major winner Rory McIlroy as one of more than half a dozen top golfers to pull out of the next month's Rio Games.
Johnson, now ranked number two in the world, was quoted by US media as saying: "This was not an easy decision for me, but my concerns about the Zika virus cannot be ignored.
"Paulina (Gretzky, Johnson's fiancee) and I plan to have more children in the near future, and I feel it would be irresponsible to put myself, her or our family at risk."
The mosquito-borne Zika virus has been linked to defects in newborn babies.
Johnson, 32, won his first major at Oakmont in June. He is the first US golfer to withdraw from the Games citing concerns over the Zika virus. Jordan's compatriot and world number three, Jordan Spieth, has said he will be going to the Games.
Other golfers to have withdrawn include US Open runner-up Shane Lowry of Ireland, Japan's Hideki Matsuyama, Australian pair Marc Leishman and Adam Scott, South African trio Branden Grace, Louis Oosthuizen and Charl Schwartzel and Fiji's Vijay Singh.
Golf is returning to the August 5-21 Olympics for the first time since 1904.
- DPA