Masked Jackson stopped by police
A worker at the supermarket in Colorado alerted police after becoming concerned that a shopper had his face covered.
Police who identified Jackson after he removed the mask said there were "no problems".
Jackson is well-known for wearing disguises in public. The star, who is facing charges of child molestation, is on holiday with his children.
Jackson's spokesman Raymone Bain said the supermarket incident was not serious.
Low profile
"The police car pulled to the side and just asked that he show his face, and he did, and that was it," Mr Bain said. "There was no altercation or any kind of encounter."
Jackson, 45, has been keeping a low profile recently but has been seen in shops in Aspen, Colorado, near the 56-acre mountain ranch where he is staying.
Mr Bain also said the star had denied claims he had checked into a drug rehabilitation clinic.
"I am appalled. Let me state for the record that I have not checked myself into any rehabilitation centre in Aspen, Colorado." a statement from the singer said.
"I am here for a few days with my children. I am outraged by these constant rumours."