Mrs May needed to secure at least 159 votes in order to retain her position as leader of the party and push on with her Brexit negotiations, just a day after cancelling a vote on her Brexit deal in the House of Commons.
The Tory leader secured 200 votes, with 117 against.
The result comes despite the Prime Minister announcing earlier today that she won't lead the party in the next election which she said would be held in 2022.
Live updates as Prime Minister Theresa May faces vote of no confidenceMrs May said securing a Brexit deal which will deliver on the result of the 2016 referendum was "now within our grasp" and said she was "making progress" in securing reassurances from EU leaders on MPs' concerns about the proposed backstop for the Irish border.
Every MP in her Cabinet swiftly issued statements of support and she was greeted by loud cheers from the Tory backbenches when she faced the House of Commons for her weekly session of Prime Minister's Questions.
By early afternoon, the number of Conservative MPs saying publicly that they would vote for her had passed the 159 required for her to survive the attempt to oust her.
The target for victory, representing half of the parliamentary party plus one, increased from 158 during the day, as the Conservative whip was restored to Burton MP Andrew Griffiths and Dover MP Charlie Elphicke.
Tom Richmond: Amid the Brexit chaos, there is one way for Theresa May to save the day – here’s howMr Griffiths, a former chief of staff to Mrs May who had been suspended over suggestive text messages, immediately confirmed he would back the PM.
However, uncertainty remained over whether public statements would translate into votes in the secret ballot taking place in a Commons committee room between 6pm and 8pm.
Failure in the ballot would have triggered a leadership contest in which Mrs May could not stand.
But the win means another challenge cannot be mounted against her position as Tory leader for a year.