Millions of passengers flying into Heathrow airport will be able to see the giant image of Jess, the 2012 heptathlon hopeful alongside the words 'Welcome to our turf.'
It is located in Thornbury Playing Fields in Hounslow, west London, about three miles from the airport.
Jess said: 'I'm thrilled to be the first face that people will see arriving into the UK for the London 2012 Games'
British Airways sponsorship manager, Luisa Fernandez, said: 'Whether you’re a Brit coming home, or an athlete arriving in for the London 2012 Games, this celebratory message reminds us all of the power of the home crowd and how important it is to get behind Team GB and ParalympicsGB.'
Jessica Ennis continued her preparations for this summer's Olympics with victory in the long jump at the Bedford International Games on Sunday.
The European heptathlon champion jumped 6.40 metres to take the triumph just ahead of Dominique Blaize (6.39m).
Ennis recently confirmed she will be competing in four events during the Olympic trials in Birmingham next month, taking part in the100 metre hurdles and high jump on Saturday, June 23 and in the long jump and 200m the following day.
The 2009 heptathlon world champion said: 'The Aviva trials is a great opportunity for me to just polish up on a few events. I'm used to doing seven events every two days, so it will be nice just to do two events on each of the days.'