Here's what you need to know about the new prime minister.
Truss has held many varied roles in the cabinet. She was elected to parliament in 2010 and in 2012 became the Parliamentary Under-Secretary of State for Childcare and Education.
In 2014, she became Secretary of State for Environment, Food and Rural Affairs and held the role until 2016.
Then she worked as the Secretary of State for Justice and Lord High Chancellor of Great Britain before becoming Chief Secretary to the Treasury.
Under Johnson she was made Secretary of State for International Trade and the Minister for Women and Equalities then became foreign secretary after Dominic Raab was removed from the role for holidaying while Afghanistan fell to the Taliban.
Truss is a born again Tory, by which we mean she used to be a Lib Dem and even campaigned against Brexit. She even backed the Remain campaign in 2016 but now supports Britain's exit from the EU.
In terms of her economic views, she is known for being a libertarian Thatcherite - that's free trade, low tax, work not welfare, slashing red tape, shrinking the public sector type Conservatism.
In a speech launching her campaign, she pledged to move away from "business-as-usual economic management," adding this had delivered "low growth for decades".
She promised to reverse April's National Insurance hike, reverse next year's scheduled rise in corporation tax and set up "low tax zones" to help attract business.
In terms of migration and the controversial Rwanda plan, Truss believes it is “completely moral” and would help to “break the business model of these appalling people traffickers who are trading in misery.”
And in terms of her stance on social issues, she is against so-called "woke" stuff." In October she told The Telegraph she had “full respect for transgender people” but that “it wouldn’t be right to have self-identification with no checks and balances in the system”.
Truss has not managed to get on with her career without ruffling a few feathers.
Last year she was slammed following reports she used £3,000 of public money on lunch at luxury private members club 5 Hertford Street.
And she's also been criticised for using government planes.
Her personal life has been under scrutiny too and she was lambasted in 2009 over an affair with a married MP.
And then there is when she has been downright odd. At the 2014 Conservative Party Conference, Truss gave a talk about food exports in the UK and went viral after speaking excitedly about opening "pork markets" and getting very emotional indeed about how much cheese the UK imports.
\u201cLiz Truss will launch her leadership bid this morning.\u201d