Here are a few of Ms Truss's stand-out quotes from her time as Prime Minister.
- At Prime Minister's Questions on October 19
"I am a fighter and not a quitter. I have acted in the national interest to make sure that we have economic stability."
- Her resignation speech on October 20
"I recognise though, given the situation, I cannot deliver the mandate on which I was elected by the Conservative Party.
"I have therefore spoken to His Majesty the King to notify him that I am resigning as leader of the Conservative Party."
- Her victory speech on September 5
"I will deliver a bold plan to cut taxes and grow our economy. I will deliver on the energy crisis, dealing with people's energy bills, but also dealing with the long-term issues we have on energy supply.
"And I will deliver on the National Health Service, we will deliver for all for our country, and I will make sure that we use all the fantastic talents of the Conservative Party, our brilliant Members of Parliament, and peers, our fantastic councillors, our MSs, our MSPs, all of our councillors and activists and members right across our country, because, my friends, I know that we will deliver, we will deliver and we will deliver.
"And we will deliver a great victory for the Conservative Party in 2024, thank you."
- Her first speech as Prime Minister on September 6
"I am confident that together we can ride out the storm. We can rebuild our economy and we can become the modern brilliant Britain that I know we can be.
"This is our vital mission to ensure opportunity and prosperity for all people and future generations."
- Announcing a two-year plan to shield Britons from the global gas crisis on September 8
"This is the moment to be bold. We are facing a global energy crisis and there are no cost-free options."
- On September 29 in her first public comments since the mini-budget market chaos
"We had to take urgent action to get our economy growing, get Britain moving and also deal with inflation.
"Of course, that means taking controversial and difficult decisions but I am prepared to do that as Prime Minister because what is important to me is that we get our economy moving, we make sure that people are able to get through this winter and we are prepared to do what it takes to make that happen."
- She acknowledges mistakes over the mini-budget on October 2
"I do want to say to people I understand their worries about what has happened this week," she told the BBC's Sunday With Laura Kuenssberg.
"I do stand by the package we announced, and I stand by the fact we announced it quickly, because we had to act.
"But I do accept we should have laid the ground better ... I have learned from that and I will make sure that in future we do a better job of laying the ground.
- In a dramatic U-turn, the plan to abolish the 45p rate of income tax for top earners is abandoned on October 3
"We get it and we have listened.
"The abolition of the 45p rate had become a distraction from our mission to get Britain moving.
"Our focus now is on building a high growth economy that funds world-class public services, boosts wages and creates opportunities across the country."
- Her speech at the Tory conference on October 5
"In these tough times, we need to step up. I am determined to get Britain moving, to get us through the tempest and put us on a stronger footing as a nation.
"I am driven in this mission by my firm belief in the British people.
"I believe that you know best how to spend your own money, to get on in life and realise your own ambitions.
"My friends, that is what Conservatism is about.
"It is a belief in freedom, in fair play and the great potential of the British people."
- She apologises for mistakes on October 17
"I wanted to act ... to help people with their energy bills, to deal with the issue of high taxes, but we went too far and too fast. I've acknowledged that."