The 21-year-old told the Mirror's Celebs on Sunday magazine that she decided to oblige the fan's request while on holiday in Greece.
"When I was in Greece with my friends I met this boy and he wanted me to tattoo his leg," said the 'All About Tonight' singer.
"I didn't just sign my name so he could get it tattooed. I actually tattooed it myself.
"He already had loads [of tattoos] and had a tattoo pen and all the special stuff and said he'd love me to do it."
Despite having no previous experience, Lott and her friends completed the artwork and then took pictures on their phones.
"I did it like my signature on the album and my friends helped with the kisses," she said.
"I have a picture on my phone. It was weird."
Lott, whose last album Young Foolish Happy reached number 18 on the UK chart, recently revealed that she is in the early stages of recording a Motown album.
Watch the video for Pixie Lott's debut hit 'Mama Do' below: