Melbourne Airport opened on 1 July 1970, when Prime Minister John Gorton inaugurated it for international operations, ending Essendon Airport's near two-decade run as Melbourne's international gateway. Domestic flights followed a year later, transferring from Essendon on 26 June 1971. In its first year, the airport handled six international airlines and 155,275 international passengers. That figure today is almost unrecognizable: the airport served over 36 million passengers in 2025, making it Australia's second busiest airport by passenger movements, after Sydney.

Adjacent to the suburb of Tullamarine, roughly 22 kilometres northwest of the Melbourne central business district, the airport is the primary gateway for the entire state of Victoria. It was deliberately built without a curfew, a distinction that matters. While Sydney imposes an 11 pm-6 am flight ban, MEL operates around the clock, making it Australia's busiest 24-hour airport and a preferred hub for freight operators and long-haul carriers whose slot times demand overnight flexibility. Qantas and Virgin Australia use it as a major hub, and Jetstar uses it as an operating base. International carriers including Emirates, Singapore Airlines, Cathay Pacific, and Qatar Airways connect the airport to the Middle East, Asia, and beyond, while Qantas operates nonstop services to Los Angeles and Dallas-Fort Worth.

The airport has a consolidated four-terminal layout spread across 1,070 hectares, with 2 intersecting runways: a 3,657-metre north-south runway and a 2,286-metre east-west runway. A third runway was approved by the Federal Government in September 2024, with construction commencing in 2025. Locally, the airport is still commonly called Tullamarine or simply 'Tulla,' a name derived from the Indigenous place name Tullamareena. It received its current name after privatisation in 1997, when it was leased to the Australia Pacific Airports Corporation for 50 years.