"They have been secretly dating for months and they are super into each other. He is super sweet and a total gentleman and Kendall loves that," a source said.
The 20-year-old model was spotted out with Clarkson, 23, on a night out in West Hollywood, reported People magazine.
Clarkson plays alongside Iggy Azalea's fiance Nick Young for the Los Angeles Lakers basketball team.
Jenner was most recently linked to Harry Styles.