"Over the next three to five years Qatar will invest £5 billion ($6.23 billion, 5.8 billion euros) in the UK economy through various investment funds and relevant parties in Qatar -- which will constitute another addition to its already successful investments in the UK," he said at the Qatar-UK Business and Investment Forum in London.
The investments will focus on energy, infrastructure, real estate and services, Sheikh Abdullah announced shortly after appearing at the investment forum, which brings together over 400 British and Qatari business leaders and senior politicians.
Qatar has already invested more than £40 billion across Britain, including in iconic real estate such as London's Shard and Canary Wharf buildings and the Harrod's department store, while the country also bought the Olympic Village following the London 2012 Olympics.
It also plans to turn the current US embassy in London into an exclusive hotel after the US moves to a new base.
British trade minister Liam Fox was also present at this week's event, which moves to the central England city of Birmingham on Tuesday for its second and final day.
Fox was keen to show the world that Britain is open for business despite leaving the EU, and said that Qatar made an ideal post-Brexit trading partner.
"We have to stop viewing things through the prism of Brexit," he told the forum.
- Qatar eyes Silicon Valley -
Signup to our newsletter and follow us on Facebook and Twitter!
"Qatar and UK are natural allies and I believe that private sector growth in both countries can enhance ties and promote foreign direct investment."
Fox said that Qatar's desire to diversify its economy and Britain's need to sell its expertise in services across the world meant trade between the two nations would be a "win-win" situation.
"No trade between the UK and Qatar should fail for lack of finance and insurance," he said, adding Britain "will be doubling finance available from UK export finance to support trade with Qatar to £4.5bn."
The minister insisted that Brexit would "accelerate the changes the UK has to undergo in a globalised world," and that other European Union members would also have to adapt to the shifting landscape of international trade.
British Prime Minister Theresa May is set to officially trigger Brexit on Wednesday.
Qatar's sovereign wealth fund chief meanwhile said that the vote to leave the European Union would not prevent its future investment in Britain.
"There is pressure from my board to diversify in terms of geography and asset class, but we are still looking, even after Brexit, for opportunities," Abdullah Bin Mohammed Bin Saud Al Thani, chief executive officer of the Qatar Investment Authority (QIA), told the forum.
He also announced plans to open an office in Silicon Valley as part of a drive to move the Qatari economy away from oil and into more sustainable sectors, such as the knowledge economy.
The QIA boss said the fund would open a San Francisco office by the beginning of next year.