Cape Town International Airport, in Cape Town, South Africa.

What is the difference between CPT and FACT?

CPT is the IATA code, used commercially — tickets, timetables, luggage tags. FACT is the ICAO code, used operationally by pilots and air traffic control, and assigned geographically by region.

What airport is CPT?

CPT is

Cape Town International Airport

Cape Town, South Africa

Why the code is CPT

CaPeTown.

The airport authority or a contemporaneous record states this directly.

The airport

IATA code: CPT
ICAO code: FACT
Airport: Cape Town International Airport
City: Cape Town, South Africa
Code origin: Documented

Cape Town's approach runs alongside Table Mountain, and the south-easterly wind that locals call the Cape Doctor regularly produces crosswinds strong enough to divert flights to Johannesburg, 1,300 km away.

The other code, FACT

Every airport has two codes. The three-letter IATA code, CPT, is the one on your boarding pass and your luggage tag, and it is assigned for commercial use. The four-letter ICAO code, FACT, is the one pilots and controllers use, and it is assigned geographically: the first letter or two identify the region, so every airport in the same part of the world shares a prefix. That is why FACT looks nothing like CPT.

Common questions

What airport is CPT?: Cape Town International Airport, in Cape Town, South Africa.
Why is Cape Town's airport called CPT?: CaPeTown.
What is the difference between CPT and FACT?: CPT is the IATA code, used commercially — tickets, timetables, luggage tags. FACT is the ICAO code, used operationally by pilots and air traffic control, and assigned geographically by region.

South Africa Capital, area, population and currency
The flag of South Africa Colours, symbols and lookalikes
Airport codes in South Africa 2 here
What airport is JNB? O. R. Tambo International Airport, Johannesburg

Sources

OurAirports — OurAirports (Public domain)

How these figures are compiled and checked