Bastarache () is a French surname of Basque origin. It was formed as a patronym of Basterreche, which itself is a topographic name for someone who lived in a house by a boundary, or on the edge of a settlement or the corner of a street. It is ultimately derived from Basque ' ("border", "edge") and ' ("house"). It was one of the original Acadian surnames.
Notable people with this surname include:
The hamlet of Bastarache in Sainte-Marie-de-Kent, New Brunswick was named after early settlers Joseph Bastarache, Isidore Bastarache or Peter Bastarache, or after Adrien Bastarache, the first postmaster.