Chiuariu was born in Botoşani to Carmen, a schoolteacher, and Alexandru, an economist, and has an older brother. The family moved to Suceava when Tudor was four; his father died three years later. His mother's parents taught in Cernăuţi until 1940, when the area was occupied by Soviet troops and they fled to near Rădăuţi–a background Chiuariu cites as a motivation for measures he took while Justice Minister to simplify procedures for members of the Romanian diaspora to regain citizenship. His father was from Grămeşti, Suceava County, born into a family of small landowners ("răzeşi"). From 1995 to 1999, Chiuariu attended the Law Faculty of the University of Iaşi.