Paltrow, who plays a washed-up star desperate to make a musical comeback in the movie, has recorded the title song for the soundtrack, due for release in October.
The track - also called 'Country Strong' - is already being played by country radio stations across the US.
The film also features country artist Tim McGraw and Gossip Girl's Leighton Meester.
Paltrow previously recorded a version of Smokey Robinson's 'Cruisin'' with Huey Lewis for 2000 movie Duets.
Country Strong opens in the US on December 22.
