The $8-billion (6.8-billion-euro) deal was signed in Doha by Qatar's Defence Minister Khalid bin Mohammed al-Attiyah and his British counterpart, Gavin Williamson.
Williamson said it was the biggest order for Typhoons in a decade, and it follows a billion-dollar deal signed by Qatar on December 7 to buy 12 French Dassault Aviation warplanes.
"These formidable jets will boost the Qatari military's mission to tackle the challenges we both share in the Middle East, supporting stability in the region and delivering security at home," said the British minister.
The deal also includes an intention for Qatar to buy further military equipment from Britain, namely the purchase of Hawk aircraft.
A memorandum of understanding was signed by the two countries for this Typhoon contract in September.
Qatar is the ninth country to sign a deal for Typhoon jets, said London.
Sunday's deal comes at a politically sensitive time for both countries.
There are heightened tensions in the Gulf, where a Saudi-led boycott of Qatar is in its seventh month.
Since June 5, Saudi Arabia, the United Arab Emirates, Bahrain and Egypt have diplomatically isolated Qatar, accusing the emirate of supporting Islamist extremists and of being too close to Shiite Iran, Riyadh's arch-rival.
Qatar denies the allegations and has accused the Saudi-led bloc of aiming to incite regime change in Doha.
It is the latest agreement in a growing list of defence deals signed by Qatar since the crisis erupted.
Doha has also struck deals with the US and Italy as well as France.
The agreement signed with France last week also included letter of intent to buy 490 VBCI armoured vehicles from Nexter, a French government-owned weapons manufacturer, in a potential deal worth 1.5 billion euros ($1.7 billion), the French presidency said.
For Britain, the deal is notable as well as it searches for major global trade deals during negotiations for its withdrawal from the European Union as Brexit talks continue.
After reaching an initial agreement last Friday on post-Brexit arrangements for citizens' rights and the Irish border, London is now set to begin talks with Brussels on a future trade deal for when Britain is scheduled to leave the EU in 2019.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
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