Divorce papers have not been filed but will be soon, the celebrity news website said Thursday, without noting how long the couple have been married or when they separated.
Zimmerman, a 29-year-old neighborhood watch volunteer, was arrested and charged in the fatal shooting of Martin, a 17-year-old, unarmed black teen, last year.
Zimmerman said he shot Martin in self-defense when the younger man attacked him after he followed Martin through a gated community where numerous burglaries had been reported.
Zimmerman was tried and acquitted of second-degree murder.
Shellie Zimmerman was given probation in August after pleading guilty to perjury when she lied in court during a bond hearing for her husband.
She told ABC News last week she was not sure whether she would stay married to George Zimmerman.