In an interview published on Friday in the Expresso newspaper, Solo said Blatter grabbed her rear end shortly before the two appeared onstage at the annual football awards event.
A representative for Solo confirmed to the Associated Press that the report was accurate and said the former goalkeeper for the US women's national team had no further comment on the matter.
Blatter could not immediately be reached for comment by AP, but the embattled former head of football's governing body told the Guardian newspaper: "This allegation is ridiculous."
