Last year’s event raised more than £7.8m for good causes in the UK.
Thousands of charities, businesses and schools across the UK have signed up to be part of this year’s Giving Tuesday.
The global day of giving, falling this year on 3 December, is expected to see millions of people across the world come together to support good causes.
Launched in America in 2012 to follow post-Thanksgiving shopping sprees such as Black Friday, Giving Tuesday has now spread around the world with events happening in more than 100 countries.
The giving movement was brought to the UK by the Charities Aid Foundation (CAF) in 2014.
Last year, more than £7.8m was raised in online donations in the UK on the day. A poll by YouGov found 1.5 million people said they were more likely to do some for charity as a result of Giving Tuesday.
Charities taking part in the 2019 campaign include Macmillan Cancer Support, Save The Children, Great Ormond Street Hospital, and Cancer Research UK.
Celebrities including Sir Richard Branson, Cara Delevingne and Dua Lipa have used Giving Tuesday to support their favourite causes, with the hashtag #GivingTuesday being used to raise awareness of the campaign.
Gráinne Mathews, who leads Giving Tuesday in the UK for CAF, said: “Giving Tuesday is a chance for all of us, no matter where we live or what we do, to help a cause close to our hearts.
“This year we are encouraging people to make a #GivingTuesdayPledge, which means you might be doing something on the day for a charity that you love or you can pledge to commit to doing something in the days and months ahead. Either way, you are still part of this incredible generosity movement.
“A #GivingTuesdayPledge could mean giving a small monthly donation to a charity or setting aside time each month for volunteering. It will all add up to make a world of difference.”