The campaign has been developed by Ben Everitt and Sophie Bodoh, and creative directors Dan Norris and Ray Shaughnessy, to persuade the public to "show off" their Fairtrade credentials.
A short film has been produced to inspire people to "show off". Featured ways to do this include a Facebook game of 14 daily challenges, some endorsed by celebrity participants, and Fairtrade-themed pranks.
The challenges require participants to submit photographs that depict imaginative ways to use Fairtrade labels.
The first challenge, Banana Smile, launched yesterday. It is supported by Zoë Ball and Norman 'Fatboy Slim' Cook, and asks challengers to submit photographs of themselves flashing a smile. The best picture will win a holiday in the Dominican Republic, home to the Asobanu Fairtrade co-operative.
'Fruit Hats' launches on 4 March, endorsed by Fearne Cotton. Participants must submit pictures of themselves wearing Fairtrade fruit hats. Winners will win tickets to see Rumer in concert and a basketful of Fairtrade apricots, raisins and mangoes.
Everitt and Bodoh said: "This year we wanted to get Britain showing off Fairtrade products and the brilliant stuff they do for developing world farmers. Fairtrade already has an amazing core campaigner group and we wanted to harness some of that pride and energy.
"We also wanted to engage a whole new audience. This was why we decided to use Facebook. It’s the perfect campaigning tool and the perfect place for showing off and spreading a message.
"It also allows us to grab the ear of tons of new people who might normally be unaware of Fairtrade Fortnight. After all, where do you have more friends than on Facebook?"
Online retailer Asos is also backing the initiative by selling Fairtrade scarves designed by Julie Verhoeven, Marios Schwab, Holly Fulton and Hussein Chalayan.
Fulton said: "It's vital to utilise cotton in a modern fashion through strong design. Hopefully, projects such as this will encourage that. I certainly look at Fairtrade in a different light now."
Recent research found that Fairtrade products are important to 47% of the UK public, and sales of Fairtrade products are set to surge in the next few years.