SAG confirmed on Tuesday evening (December 13) that Moore is to be presented with the award in recognition of "her career achievement and humanitarian accomplishment".
Moore's former co-star Dick Van Dyke will present her with the accolade at the 18th Screen Actors Guild Awards next month.
The actress's breakthrough role - for which she won two Emmy Awards - was as Van Dyke's on-screen wife Laura Petrie in The Dick Van Dyke Show. She soon progressed to her own sitcom, The Mary Tyler Moore Show, which won 29 Emmys during its seven-year run.
She was nominated for an Oscar in 1980 for her role as Beth Jarrett in Robert Redford's directorial debut Ordinary People.
In recent years, Moore has made guest appearances on That '70s Show and Hot in Cleveland, where she appeared opposite her former Mary Tyler Moore Show co-star Betty White for the first time since 1977.
Moore, who was diagnosed with type 1 diabetes in the 1970s, is international chairman of the Juvenile Diabetes Research Foundation and a supporter of several animal welfare charities.
She joins a long list of previous Screen Actors Guild Life Achievement Award recipients which includes Kirk Douglas, Elizabeth Taylor, Clint Eastwood, James Earl Jones and Julie Andrews.
The 18th Screen Actors Guild Awards take place at the Shrine Exposition Centre in Los Angeles on Sunday, January 29, 2012.
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