The sale of Fairtrade goods rose 81% in 2007 to reach £493m, according to figures from the Fairtrade Foundation.
Bananas are a popular Fairtrade item
Bananas accounted for more sales than any other Fairtrade item, at £150m, while Fairtrade cotton sales saw the biggest rise, up 660% to nearly £35m.
The figures are estimates made by the foundation using wholesale values.
To earn a Fairtrade label, firms must pay local producers a fair price, and invest further to improve working conditions and local sustainability.
"After years of chipping away, Fairtrade is finally beginning to make some significant impression on the way we trade," said Harriet Lamb, executive director of the Fairtrade Foundation.
While banana sales increased by 130% year-on-year, Fairtrade coffee sales rose 24% to more than £117m.
The news comes after sugar firm Tate & Lyle said the sugar it sells in shops will become Fairtrade accredited by the end of next year, making it the largest UK firm to carry the label.
The Fairtrade Foundation is the UK organisation that hands out the Fairtrade label to firms that meet international standards.
The data is being released as Fairtrade fortnight begins, in a bid to raise public awareness.