St. Thomas may be:

• one of the Saints:
  • Thomas, the apostle
  • Thomas Becket died 1170
  • Thomas Aquinas (1225-1274)
  • Thomas More (1478-1535)

• one of these islands:
  • Saint Thomas, United States Virgin Islands
  • São Tomé, part of São Tomé and Príncipe

• one of these other place names:
  • Canada: St. Thomas, Ontario
  • France: Saint Thomas, Aisne
  • United States of America
    • St. Thomas, Missouri
    • St. Thomas, North Dakota
    • St. Thomas Township, Pennsylvania

• one of these churches:
  • Saint Thomas Christians in India
  • St Thomas Church, Southwark
  • St Thomas, Kolkata, Kolkata

• one of these hospitals:
  • St Thomas Hospital, Southwark

• a university:
  • St. Thomas University, Fredericton, New Brunswick, Canada

• a computer game, St. Thomas