One who hears; also a diminutive of Silas or Simon
As a standalone name, Si is often a diminutive of Simon, meaning 'he has heard,' or Silas, meaning 'of the forest.' In various East Asian cultures, it can have different meanings depending on the characters used, such as 'thought' or 'four.' In the US, it is most recognized as a vintage nickname that occasionally stands alone.
Fewer than 5 boys were named Si in 2025.
US births per 5-year period, 1990–present (SSA data).
Television personality known as Uncle Si on Duck Dynasty
American trombonist and big band leader
Early 20th-century professional ice hockey player
