Romero was born and brought up in Colorado Springs, the United States. He hails from Yaqui, Cherokee, and Mexican heritage. He was born to his mother named Ginny and his father named Alfonso Antonio Romero. They have an interracial marriage.
When John was young, he was inclined to video games. The arcade game named Space Invaders (1978) and the maze chase arcade game named Pac-Man (1980) made him more interested in video games. These were the two games that influenced his childhood significantly and got him thinking about the design of video games. Nasir Gebelli has been his favorite programmer who has inspired him a lot. Some of the other programmers who have influenced his childhood were Bill Budge, and Shigeru Miyamoto.
