Harry Reid International Airport, in Las Vegas, United States.

What is the difference between LAS and KLAS?

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

What airport is LAS?

LAS is

Harry Reid International Airport

Las Vegas, United States

Why the code is LAS

The first three letters of Las Vegas.

The airport authority or a contemporaneous record states this directly.

The airport

IATA code: LAS
ICAO code: KLAS
Airport: Harry Reid International Airport
City: Las Vegas, United States
Code origin: Documented

It was McCarran International until 2021, when it was renamed for Senator Harry Reid; the code did not change, because LAS was never derived from McCarran in the first place. Slot machines in the terminal are a genuine oddity — most jurisdictions do not permit gambling airside.

The other code, KLAS

Every airport has two codes. The three-letter IATA code, LAS, is the one on your boarding pass and your luggage tag, and it is assigned for commercial use. The four-letter ICAO code, KLAS, 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 KLAS looks nothing like LAS.

Common questions

What airport is LAS?: Harry Reid International Airport, in Las Vegas, United States.
Why is Las Vegas's airport called LAS?: The first three letters of Las Vegas.
What is the difference between LAS and KLAS?: LAS is the IATA code, used commercially — tickets, timetables, luggage tags. KLAS is the ICAO code, used operationally by pilots and air traffic control, and assigned geographically by region.

United States Capital, area, population and currency
The flag of United States Colours, symbols and lookalikes
Airport codes in United States 32 here
What airport is JFK? John F. Kennedy International Airport, New York
What airport is LAX? Los Angeles International Airport, Los Angeles
What airport is ORD? O'Hare International Airport, Chicago
What airport is ATL? Hartsfield-Jackson Atlanta International Airport, Atlanta
What airport is MCO? Orlando International Airport, Orlando
What airport is DFW? Dallas/Fort Worth International Airport, Dallas
What airport is EWR? Newark Liberty International Airport, Newark
What airport is SFO? San Francisco International Airport, San Francisco

Sources

OurAirports — OurAirports (Public domain)

How these figures are compiled and checked