Flying boat services were resumed with American-built Consolidated PBY Catalinas on 10 July 1943, with flights between Swan River, Perth and Koggala lake in Ceylon (now Sri Lanka). This linked up with the British Overseas Airways Corporation (BOAC, the successor airline to Imperial Airways) service to London, maintaining the vital communications link with England.

In 1944 the Catalinas were augmented by conventional Consolidated B-24 Liberators, flying from Ratmalana via RAF Minneriya for refuelling and then across the ocean to Learmonth. Later, Avro Lancastrians were flown on the route. They flew from Sydney to Gawler, stopping in Adelaide for refuelling, and on to Learmonth for the overnight stage. The service was renamed the Kangaroo Service and the passenger award became The Order of the Longest Hop. It was on this route that the Kangaroo logo was first used. After the war, the return trip could also go from Colombo to the Cocos Islands, then to Perth on to Sydney. These flights continued until 5 April 1946.

In 1947, QEA was nationalised, with the Australian Labor government led by Prime Minister Ben Chifley buying the shares owned by BOAC, followed by those of QANTAS Limited. Nationalised airlines were normal at the time, and the Qantas board encouraged this move. After the completion of the buyout, QANTAS Limited was wound up and liquidated to shareholders.

Shortly after nationalisation, QEA began its first services outside the British Empire to Tokyo via Darwin and Manila with Avro Lancastrian. These aircraft were also deployed between Sydney and London in co-operation with BOAC, but were soon replaced by Douglas DC-4s in 1949. Services to Hong Kong began around the same time. In 1947 the airline took delivery of Lockheed L-749 Constellations and these took over the trunk route to London. Flying boats again entered the fleet from 1950, when the first of five Short Sandringham aircraft entered service for flights between the Rose Bay flying boat base on Sydney Harbour and destinations in New Caledonia, New Hebrides, Fiji, New Guinea and Lord Howe Island.

In 1952 Qantas expanded services across the Indian Ocean to Johannesburg via Perth, the Cocos Islands and Mauritius, calling this the Wallaby Route. The network expanded across the Pacific to Vancouver via Auckland, Nadi, Honolulu and San Francisco in early 1954 when it took over the Southern Cross Route of British Commonwealth Pacific Airlines (BCPA). The first of the airline's Lockheed 1049 Super Constellations was delivered in early 1954.

In January 1958 Qantas became the second round-the-world airline, flying Super Constellations west from Australia to London through Asia and the Middle East on the Kangaroo route, and east to London on the Southern Cross route. It took delivery of new turboprop Lockheed Electra aircraft in 1959.

In September 1956 Qantas ordered the Boeing 707 jet airliner and the first was delivered in June 1959. This order made the airline the first customer for the type outside the US. In March 1960 the airline ordered six of the turbofan derivative, Boeing 707-138B, with delivery scheduled for the following year. The first Qantas jet service was on 29 July 1959 from Sydney to San Francisco via Nadi and Honolulu. On 5 September 1959 Qantas became the third airline to fly jets across the North Atlantic, after BOAC and Pan Am, operating between London and New York as part of the service from Sydney.

Air travel grew substantially in the early 1960s, so Qantas ordered the larger Boeing 707-338C series of aircraft. While waiting for these to be delivered, Qantas operated six de-Havilland Comet 4 aircraft wet leased from BOAC between 7 November 1959 to 30 May 1963. The same year, Qantas placed early options on the new Concorde airliner but the orders were eventually cancelled. Also in 1966, the Fiesta route opened from Sydney to London via Fiji, Tahiti, Mexico City, Acapulco, Nassau and Bermuda.

In September 1965 Qantas launched the first V-Jet service on the Kangaroo Route, via Kuala Lumpur, Malaysia. In 1967 the airline placed orders for the Boeing 747. This aircraft could seat up to 350 passengers, a major improvement over the Boeing 707. Orders were placed for four aircraft with deliveries commencing in 1971. Also in 1967, Qantas Empire Airways changed its name to Qantas Airways, the name of the airline today.

At the end of the 70's, Qantas placed options on two McDonnell Douglas DC10 aircraft for flights to Wellington, New Zealand. These were not taken up, and two Boeing 747SPs were ordered instead. In March 1979, Qantas operated its final Boeing 707 flight from Auckland to Sydney, and became the only airline in the world to have a fleet that consisted of Boeing 747s only. That same year Qantas introduced Business class, it was the first airline in the world to do so.

In 1984, a new refreshed logo designed by Hans Hulsbosch and his company Hulsbosch Communications debuted, dropping the wings from the kangaroo. The Boeing 767–200 was introduced in 1985, for New Zealand, Asia and Pacific routes. The same year, the Boeing 747–300 was introduced, featuring a stretched upper deck. The Boeing 747 fleet was upgraded from 1989 with the arrival of the new Boeing 747-400 series.

In 1990, Qantas established Australia Asia Airlines to operate services to Taiwan. Several Boeing 747SP and Boeing 767 aircraft were transferred from Qantas service. The airline ceased operations in 1996. The Australian Government sold the domestic carrier Australian Airlines to Qantas in August 1992, giving it access to the national domestic market for the first time in its history. The purchase saw the introduction of the Boeing 737 and Airbus A300 to the fleet, though the A300s were soon retired. Qantas was privatised in March 1993, with British Airways taking a 25% stake in the airline.

In 1998, Qantas co-founded the Oneworld alliance with American Airlines, British Airways, Canadian Airlines, and Cathay Pacific. The alliance commenced operation in February 1999. Qantas ordered twelve Airbus A380-800s in 2000, with options for twelve more. Eight of these options were exercised in 2006, bringing firm orders to twenty. Qantas was the third airline to receive A380s, after Singapore Airlines and Emirates.

The main domestic competitor to Qantas, Ansett Australia, collapsed on 14 September 2000. Market share for Qantas immediately neared 90%, with the relatively new budget airline Virgin Blue holding the remainder. To capitalise on this event, Qantas ordered Boeing 737–800 aircraft. At the same time, Virgin Blue announced a major expansion in October 2001, Qantas responded by creating a new cut-price subsidiary airline, Jetstar Airways.

Qantas received its first Airbus A330, for its trunk domestic routes and overseas operations in 2002. Qantas also expanded into the New Zealand domestic air travel market, firstly with a shareholding in Air New Zealand and then with a franchise takeover of Ansett New Zealand. In 2003, Qantas, introduced the Jetstar low cost model to New Zealand. British Airways sold its 18.5% stake in Qantas in September 2004.

On 14 December 2005 Qantas announced an order for 115 Boeing 787–8 and 787– 9 aircraft. The aircraft allowed Qantas to replace its Boeing 767–300 fleet, increase capacity and establish new routes. The first of the 787s were originally scheduled to be delivered in August 2008, with the 787-9s coming in 2011. However, on 10 April 2008 Qantas announced that the intended August delivery of the 787s has been delayed until 2017.

Also in 2008 the first Qantas Airbus A380 was handed over by Airbus at a ceremony on 19 September. Qantas' first route for the A380 was Melbourne to Los Angeles beginning on 20 October 2008, then from Sydney to Los Angeles. Subsequent aircraft to be delivered will further expand services, initially on the Kangaroo Route.

On 2 December 2008, British Airways confirmed that talks were underway regarding a possible merger between the two companies. However, the two companies called off their merger discussions over ownership issues. On 29 December 2008, Qantas flew its last scheduled Boeing 747–300 service, operating from Melbourne to Los Angeles via Auckland. In the wake of the Global Financial Crisis Qantas says it could "ditch" some first class seats on some short International routes to maximise profits.

In 2012, Qantas reported a loss, citing high fuel prices, intense competition and industrial disputes. This was the first full year loss since Qantas was fully privatised 17 years previously, in 1995, and led to the airline cancelling its order of 35 new Boeing 787 Dreamliner aircraft, to reduce its spending. Also in that year on 26 March 2012, Qantas announced it would set up Jetstar Hong Kong with China Eastern Airlines Corporation, which was intended to begin flights in 2013, but became embroiled in a protracted approval process.

Qantas and Emirates began an alliance on 31 March 2013, in which their combined carriers offered 98 flights per week to Dubai, Losses continued into 2014 reporting year. In February 2014 additional cost-cutting measures to save A$2 billion, including the loss of 5,000 jobs. The carrier also reduced the size of its fleet by retiring aircraft and deferring deliveries; and planned to sell some of its assets.

The airline returned to profit in 2015, it also sold its lease of Terminal 3 at Sydney Airport, which was due to continue until 2019, back to Sydney Airport Corporation. After the airline profits share in 2015, Qantas announced that it had ordered eight Boeing 787-9s to serve the first non-stop intercontinental routes from Australia to London, starting with Perth and eventually adding Melbourne and Sydney to the network.

In October 2016, Qantas' flying kangaroo was redesigned. The triangular container was reshaped to resemble the tail fin of a modern aircraft. The roo graphic was changed by losing some details such as the arms and bolstered with some gradated areas to simulate a three-dimensional feel.