Jenner, 19, who has been walking runways for Chanel and Balmain at Paris fashion week, has been posting photos of herself wearing Calvin Klein on her Instagram since last year, often tagging the line to show her support, reported the New York Post.
Jenner's Instagram posts are similar to those singer Justin Bieber posted on his own feed before he was announced in January as a spokesman for Calvin Klein Jeans.
She would follow iconic female faces of Calvin Klein Jeans including Brooke Shields and Kate Moss.