Antonina Roll-Mecak was born in Romania. Her father was an engineer and scientist. Growing up, her father tutored her in Newtonian physics, creating complex pulley-related problems for her to solve, and taught her the principles of programming through Fortran punch cards. During summers, she attended camps focused on math and science, and trained for academic Olympiads. She also spent summer breaks training for and competing in piano competitions, and as a child she aspired to be a concert pianist.