Nerijus Numavičius was born in Šilalė, a small town in Lithuania, the eldest of six children: three brothers and three sisters. Later the family moved to Šilagalys (near Panevėžys). He graduated from Panevėžio „Žemynos“ progimnazija. In 2001, Numavičius earned bachelor's degree in medical sciences from the Faculty of Medicine of Vilnius University, where he studied public health.