Bartosiewicz ({{IPA-pl|bartɔˈɕɛvitʂ}}) is a surname of Polish-language origin. It may refer to:

• Edyta Bartosiewicz (born 1965), Polish rock singer, composer and songwriter
• Peter Bartosiewicz (born 1942), pair skater who competed for Czechoslovakia
• Thomas J. Bartosiewicz (born 1948), New York state senator 1976–1988

• Materials Testing Reactor
• Material Testing Program EA (Edgewood Arsenal) numbers
• Material Thangz
• Materialtretthet
• Material witnesses
• Material World Charitable Foundation
• Materia (Novembre album)
• Materia prima
• Materija 1 Mass Grave
• Materine uzance
• Materine užance
• Mater Larum
• Mater Misericordiae Hospital, Brisbane
• Mater Misericordia Hospital
• Materna (disambiguation)
• Maternal and child healthcare in Bolivia
• MATERNAL AND CHILD HEALTH IN TANZANIA
• Maternal and child health in Tanzania
• Maternal and Newborn Health in Ethiopia Partnership - MaNHEP
• Maternal antibodies
• Maternal antibody
• Maternal behavior
• Maternal bleeding
• Maternal care
• Maternal changes in pregnancy