The journey from London to Australia, dubbed 'The Kangaroo Route', was once a flight which took 12 days.
Passengers on the first British Airways flight, which departed on April 13 in 1935, paid more than $23,400 for a one way ticket.
Eighty years on, the airline continues to fly a similar course as the original Kangaroo route but now takes about 23 hours from London to Sydney and costs just $1700 for a return ticket......
To celebrate this milestone anniversary since its first flight to Australia, Hollywood actress Naomi Watts has starred in a retro photo shoot to recreate a vintage poster for British Airways.
The British-born Australian actress posed in a vintage swimsuit for a modern version of the classic poster, which was used decades ago to promote flying to the exciting new country of Australia in the South Pacific. The journey from London to Australia, dubbed 'The Kangaroo Route', was once a flight which took 12 days
The British-born Australian actress posed in a vintage red swimsuit for a modern version of the classic poster, which was used decades ago to promote flying to the new and exciting destination Down Under.
Watts was born in Kent, south-east England, before emigrating to Australia with her family at the age of 14.
'It has been great to go back in time with British Airways and recreate an iconic poster from such a glamorous era,' the 46-year-old said.
'I love the vintage style from the golden age of travel so it was really fun to bring this to life.
'Eighty years is an incredible landmark for British Airways and with a personal connection to both countries, it's really special to take part in celebrating the history of travel between Australia and the UK.'
The first British Airways flight between the two countries was launched by the airline's predecessor Imperial Airways in conjunction with Qantas Empire Airways.
It then merged with British Airways to become the British Overseas Airways Corporation (BOAC) in 1940.
The airline's first 12,754 mile trip from London to Australia, which landed in Brisbane, took 12 days as it stopped in Baghdad, Delhi, Bangkok and Singapore.
The airline began its weekly service to Australia in 1945 which later became known as 'The Kangaroo Route'.
Today the airline operates daily flights between London and Sydney via Singapore, just as the original Kangaroo route did.
Since that first flight 80 years ago, British Airways has carried more than 1.3 billion customers globally - flying about 36 million customers per year to more than 179 destinations, in 75 countries.
'Flying customers that distance, across multiple continents to Australia had never been done before and was by no means an easy feat in the 1930s,' Keith Williams, executive chairman of British Airways, said.
'We continued to invest in the latest aircraft and cabins so that customers in Australia can travel in comfort and enjoy the British service we're renowned for - just as they did 80 years ago.
'As the only European airline to still fly to the country, we are extremely proud to be celebrating 80 years of connecting our two great nations.'