- 5 Abecco, Signor
- 1 Abednego (Biblical figure)
- 1 Abel (Biblical figure)
- 42 Abele, Julian, 1881-1950.
- 1 Abele, Marguerite
- 1 Abele, Nadia
- 1 Abendberg (Hospital)
- 1 Aberdeen, George Hamilton Gordon, Earl of, 1784-1860
- 1 Abington Township, Pennsylvania
- 5 Abington, Pennsylvania
- 2 Abishag (Biblical figure)
- 4 Abolition movement
- 2 Abolitionists
- 10 Abraham (Biblical patriarch)
- 2 Abraham (Biblical Patriarch)
- 1 Abstract artists
- 12 Abstract Expressionist
- 1 Abstraction
- 1 Abuse
- 1 Acacius, of Mount Ararat, Saint
- 1 Academic costume
- 1 Academic libraries (buildings)
- 6 Academies (organizations)
- 20 Academy of Music
- 1 Academy of Natural Sciences
- 31 Academy of Natural Sciences of Philadelphia
- 1 Academy of Notre Dame
- 1 Academy of the Sisters of Notre Dame
- 8 Academy Road
- 20 Acanthus
- 2 Accarisi, Lodovico
- 40 Accidents
- 6 Accordions
- 8 Account books
- 17 Accounts
- 1 Acebal y Menendez (Firm)
- 1 Achievements
- 3 Achilles (Greek mythology)
- 1 Acinonyx jubatus (species)
- 1 Ackers (Firm)
