Hamad International Airport, in Doha, Qatar.

What is the difference between DOH and OTHH?

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

What airport is DOH?

DOH is

Hamad International Airport

Doha, Qatar

Why the code is DOH

DOHa. The code moved from the old Doha International Airport.

The airport authority or a contemporaneous record states this directly.

The airport

IATA code: DOH
ICAO code: OTHH
Airport: Hamad International Airport
City: Doha, Qatar
Opened: 2014
Code origin: Documented

Hamad is built almost entirely on reclaimed land — about 60 per cent of its area was sea. It became Qatar Airways' sole hub in 2014, and the airline's response to the 2017 blockade by neighbouring states was to route everything around their airspace, which added hours to some flights and did not stop them.

The other code, OTHH

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

Common questions

What airport is DOH?: Hamad International Airport, in Doha, Qatar.
Why is Doha's airport called DOH?: DOHa. The code moved from the old Doha International Airport.
What is the difference between DOH and OTHH?: DOH is the IATA code, used commercially — tickets, timetables, luggage tags. OTHH is the ICAO code, used operationally by pilots and air traffic control, and assigned geographically by region.

Qatar Capital, area, population and currency
The flag of Qatar Colours, symbols and lookalikes
Airport codes in Qatar 1 here

Sources

OurAirports — OurAirports (Public domain)

How these figures are compiled and checked