David Beckham and Victoria Beckham took their only daughter to meet the Poker Face singer backstage at the Capital FM Jingle Bell Ball on Sunday night.
"Victoria and David, along with Harper, were taken to meet Lady Gaga backstage, and proudly told her that their daughter is her biggest fan," a source told the MailOnline.
"They also said that even though she's only two years old, she already sings Gaga songs!"
It's not just her former Spice Girl mum's musical footsteps that the adorable little girl might be following in.
Fashion designer Victoria revealed earlier this year that Harper has already developed an interest in her mum's enviable wardrobe.
"She definitely has a point of view," 39-year-old Victoria said before her spring/summer 14 show at New York Fashion Week.
"If I'm going out for the night I'll come downstairs and she'll say 'oh nice dress mummy' or 'nice handbag mummy'."
However, Victoria draws the line at letting her daughter get in on her beauty routine though.
The mum-of-four revealed in May that she never puts make-up on in front of her daughter in a bid to stop her growing up too quickly.
Speaking to the Sun, Victoria admitted, "I can't put make-up on when Harper's around because she would join me immediately."