Mary Margaret O'Reilly (haihuwa 14 ga Oktoba 1465)   - 6 ga Disamba, 1949) ta kasance wata ma'aikaciyar gwamnati ne na Amurka wanda ta yi aiki a matsayin Mataimakin Darakta a Ofishin Mint na Amurka daga shekarar 1924 zuwa 1938. ta kasance daga cikin manyan ma’aikatan mata na gwamnatin Amurka na lokacin ta, ta yi aiki a Mint har tsawon shekaru 34, a lokacin da ta kasance mataimakiyar darekta a lokacin babu Jagorar Mint . O'Reilly an haife shi a Springfield, Massachusetts ga dangin baƙi na Irish . Lokacin da ta girma a wannan jihar, ta bar makarantar a kusan shekara 14 don taimakawa tallafawa mahaifiyarta da gwauraye. Wataƙila ta fara aiki a masana'antar masana'anta ta gida, ta sami horo na musamman a makarantar dare kafin ta fara aiki a matsayin magatakarda a cikin Worcester shekaru goma sha takwas. A cikin 1904, O'Reilly ya sami matsayi a ofishin Mint, wanda ya haifar da matsawa zuwa Washington, DC Ta tashi cikin sauri a cikin ofishin ofis – abin da baƙon abu ba ne ga mace a wancan lokacin – kuma ana kiranta akai-akai don yin shaida a gaban Majalisar Wakilai .