The 19-year-old "Keeping Up With the Kardashians" star chose the colour white for her tattoo, while Hailey picked red for hers, which is on the inside of their middle fingers, reported E! Online.
Hailey shared the tattoo picture on Snapchat but deleted the photo shortly after.
According to sources, they "always wanted to get the tattoo" and does not mean that they had a heartbreak.
Kendall is reportedly dating Nick Jonas, 22, and they are a "very new" couple who are taking it very slowly despite spending a lot of time together, the source said.