Reese Witherspoon Is Wearing Giorgio Armani at the 2015 SAG Awards

Reese Witherspoon - P 2015

Reese Witherspoon - P 2015

America's sweetheart was radiant in a one-shoulder white dress.

Reese Witherspoon may have transformed into a rough and rugged hiker for her role as Cheryl Strayed in Wild, but at Sunday evening's SAG Awards, the actress was back in top red-carpet form. 

PHOTOS See The Complete SAG Awards Red Carpet, Here

Wearing a fitted white custom gown by Giorgio Armani, Witherspoon paired the chic look with a sleek ponytail and bold red lip.

See THR's Complete SAG Awards Coverage, Here