The 53-year-old hate preacher left Belmarsh prison shortly after midnight on Sunday morning in a police convoy. He was taken to RAF Northholt, from where he was flown in a private jet to Jordan.
He is expected to land in the Middle Eastern country around 8am today.
The Government has been trying to deport Qatada to Jordan, where he was convicted of terror charges in his absence in 1999, for over eight years but had been prevented from doing so by the EU court of human rights.
'We as the UK need to look at our relationship with the European Court and we need to ensure that in future we are able to deport people more quickly.
'I am pleased that Abu Qatada has been deported, I think the British public will be pleased about that. They have wanted that for some time, this Government has now achieved it.'
Mrs May said she had no concerns about Qatada's treatment once he reaches Jordan because of assurances hammered out in the treaty with the Jordanian government.
Following numerous courtroom battles, it was a treaty signed between the UK and Jordan that finally secured Qatada's departure, giving the radical preacher the assurances he needed to leave his taxpayer-funded home behind.
The agreement, announced by the Home Secretary earlier this year, aimed to allay fears that evidence extracted through torture will be used against the father of five at a retrial.
In a shock decision, Qatada pledged in May to leave Britain - with his family in tow - if and when the treaty was fully ratified, a process that to the relief of many, concluded earlier this week.
MP Keith Vaz, chairman of the Home Affairs Select Committee, said: 'Only 446 days after the Home Secretary said Abu Qatada would be on a plane shortly, he has finally reached the end of the runway.
'In the end, it was the king of Jordan who secured his departure by agreeing to this treaty.
'The Home Secretary's legal advisers will have questions to answer as to why they didn't conceive of this scheme earlier which would have prevented a cost to the taxpayer of £1.7 million.'
The Jordanian government published a treaty designed to trigger Qatada's deportation in its official gazette, leaving just a handful of legal steps before it is brought into law.
Qatada previously volunteered to leave his taxpayer-funded home in Britain for Jordan - with his family in tow - as soon as the treaty is ratified by both countries.
found during the search of his home.