It recently emerged that 22-year-old Stewart cheated on boyfriend of three years Pattinson with her "Snow White and the Huntsman" director Rupert Sanders.
The 26-year-old 'Judas' hitmaker was so moved by the couple's plight that she posted a message on Twitter.
"Geez this kirstew rob stuff is brutal. Makes me sad the way press acts. Hope they're ok (sic)," Gaga posted.
Stewart publicly confessed to the fling with Sanders. She issued a statement saying, "I'm deeply sorry for the hurt and embarrassment I've caused to those close to me and everyone this has affected. This momentary indiscretion has jeopardised the most important thing in my life, the person I love and respect the most, Rob. I love him, I love him, I'm so sorry."
Gaga's message of support has been re-tweeted over 10,000 times.
Although Stewart and Sanders met on the set of "Snow White and the Huntsman", the affair is alleged to have happened after filming had finished.
Sanders is married to Liberty Ross, who also starred in the film. They have two children together.
