The deal is the biggest for any football club, the Spanish champions said on their website, and will net the Catalans, the second-richest club by income behind arch rivals Real Madrid, as much as 170 million euros.
The total includes 15 million euros for commercial rights for the current season and a bonus for winning titles that could be as much as 5 million, Barca added.
"With this accord, Barca becomes the undisputed brand leader in world football, far ahead of international rivals," Javier Faus, a club vice president, told a news conference.
He added that the fresh injection of cash would help strengthen sporting projects, though he cautioned that the heavily-indebted club's financial situation remained delicate.
"Less so, but still delicate and the austerity plan led by the director general will be carried forward 100 percent," he said.
"It's a non-commercial brand, it's a foundation and an NGO (non-governmental organisation) from a small country, at once progressive and traditional, which aims to raise its profile in the world through education and sport," added Faus.
Last week the tiny Gulf state was chosen by football's governing body FIFA to host the World Cup in 2022, when it will become the first Arab country to stage the finals, and Barca coach Pep Guardiola was one of the ambassadors for the bid.
The club are one of the few in world football not to have a corporate logo on their first-team shirts, instead displaying the name of the United Nations Children's Fund, UNICEF, for which they pay the organisation 1.5 million euros a year.
The agreement also includes a commitment for Barca to play one friendly per season, not necessarily in Qatar, and the Qatar Foundation will take part in joint projects with UNICEF and the club's own foundation.
Real Madrid's 23-million-euro deal with Internet bookmaker bwin was the next biggest.
