Melanie Martinez revealed the origin of her surname in an interview with Maybelline Las Vegas. She said:

"I used to have a boyfriend named Martin. He came from a village where people had cringeworthy language. Instead of "girlfriend", they said "ass". It was hard for others to remember my name, therefore they basically called me "Martin ass". Later, I wanted to give it some Latino flavor, and I changed it to "Martinez", making it my surname."