The name "Pompey" for Portsmouth likely originates from a sailor's slang and naval history. The most accepted explanation is that it is a drunkard's slurred or shortened pronunciation of "Portsmouth Point," an area in Old Portsmouth popular with sailors and full of taverns. Ships entering Portsmouth Harbour would log "Pom.P" as an abbreviation of Portsmouth Point, and this shorthand made its way into local slang and eventually became widely used to refer to the city and its football club. Other popular theories include:
- A link to a captured French ship named "La Pompee" used as a prison ship in Portsmouth.
- Sailors who climbed Pompey's Pillar in Egypt becoming known as "Pompey Boys."
- A reference to the Roman general Pompey mentioned in Shakespeare's Anthony and Cleopatra.
- A resemblance to the Indian port of Bombay (part of a dowry involving Portsmouth).
However, the sailor slang origin tied to Portsmouth Point and its abbreviation "Pom.P" is the strongest and most widely accepted reason why Portsmouth is called Pompey.