Fiona Stewart may refer to:

• Fiona Stewart (author) (born 1966), Australian author and euthanasia activist

• Cassandra software
• Cassandra (song)
• Cassandra Steen discography
• Cassandra (story)
• Cassandra: The Third Eye Saga
• Cassandra: Warrior Angel
• Cassandra Warrior Angel
• Cassandra Wilson (dancer)
• Cassandra’s Ears
• Cassandre (1901-1968)
• Cassandre (1901–1968)
• Cassandre Beaugrand
• Cassandre (opera)
• Cassandria
• Cassandro
• Cassandro el Exotico
• Cassandro (wrestler)
• Cassanga language
• Cassani
• Cassano allo Ionio
• Cassano d'Adda railway station
• Cassano (disambiguation)
• Cassano Magnago HC
• Cassarate (river)
• Cassard