The 23-year-old actress - who plays cheerleader Brittany Pierce in the show - has been signed by the cosmetic company to represent its various brands, and both agree they are well suited because of the nature of Heather's character.
She said: "Brittany is the biggest flirt on 'Glee' so there's that - not to mention I'm obsessed with the Flirt makeup."
Julie Howard - senior vice president of global marketing and brand development for Flirt's parent company BeautyBank - praised the starlet, saying: "Heather is a perfect fit for the Flirt brand. She's fun, playful, young and talented."
Heather will first promote All That Lash, a new mascara the brand launched in February, and Luv-a-Licious, a scent set to his stores in April.
Her role will include making in-store appearances, and hosting an online contest to find a star to appear in an online viral video for the brand.