The photo showed the 26-year-old hugging her knees to her chest as she reclined in an armchair. She also wore fairly little make-up and her long blonde hair was hanging loose down her shoulders, reported Sun Online.
Gaga, who is known for her erratic dressing sense, has previously posted semi-nude photos online as well.
The 'Born This Way' hitmaker will soon make her acting debut in "Machete Kills", starring alongside Amber Heard, Sofia Vergara and Mel Gibson.
Gaga will play a femme fatale called La Chameleon.
