Backed by the Archbishop of Canterbury, the campaign encourages people to pray for other to find Jesus.
Last year over 100,000 joined in during the 10 days between Ascension and Pentecost.
This year it's set to go even bigger.
Emma Buchan, project leader for the Archbishop's Evangelism Taskforce, who heads up Thy Kingdom Come, said: "The global response to the campaign this year has been overwhelming.
"We've heard from churches across the world, including different denominations and traditions, who have all pledged to get involved from South Africa to Canada and from the Brazil to Hong Kong.
"Each place is organising the time in their own way, for example in Hong Kong they are planning big celebrations in the cathedrals and establishing a network of 'prayer warriors'. That's the beauty of Thy Kingdom Come."
A special service is being broadcast on BBC1 on Sunday as part of the campaign while across the UK people will gather for 34 special beacon services in Cathedrals.