The singer currently stars as Elliot in the Fox musical comedy, which returns after a midseason hiatus on February 25.
Lambert - who has been acting as a mentor for this season's American Idol contestants - has covered The Darkness track 'I Believe in a Thing Called Love' for the upcoming episode 'Frenemies'.
The behind-the-scenes clip features Lambert and Chris Colfer filming the song number in a guitar shop.
The episode will focus on different friendships between people who may not always get along, including Elliot and Kurt, and Santana and Rachel.
Lambert's role of Elliot in Glee was confirmed as not permanent back in December.