Mary Bell (born 1957) is an English woman who at age 11 was convicted of the manslaughter of two younger boys.

Mary Bell may also refer to:

• Mary A. Bell (1873–1941), African-American artist
• Mary Hayley Bell (1911–2005), English actress, writer and dramatist
• Mary Bell (aviator) (1903–1979), Australian aviator
• Mary Bell (Civil War nurse) (1840–?), American nurse
• Mary Bell (politician) (1885–1943), Scottish politician
• Mary L. Bell (1901–1995), first African-American to own and operate a radio station in the city of Detroit, Michigan
• Mary Hemings Bell (1753–after 1834), freed slave once owned by U.S. president Thomas Jefferson
• Mary Ann Bell (fl. 1806–fl. 1831), British fashion merchant, fashion designer and fashion journalist
• Mary Bell, disguised herself as a man and fought in the American Civil War for the Confederacy, see Mary and Molly Bell
• Mary Bell (1844–1874), Christian missionary, see Mary and Annie Bell

Fiction[edit]

• Floral Magician Mary Bell, a 1992 anime series, or its title character, Mary Bell
• Marybell, a main character in the manga Poe no Ichizoku by Moto Hagio
• Marybell, a manga by Kimiko Uehara