Ruth just hours after Boris Johnson revealed he will be shutting down Parliament for a month.
The Tory admitted a "conflict" with the Prime Minister over Brexit as she officially resigned, but also said she was stepping down to spend time with her new baby son.
She clashed with Johnson regularly over the years and has been a vocal critic of his policies and actions.
She's never been afraid to go blue-on-blue, and she's also taken on a number of her other Tory colleagues on issues close to heart.
Davidson has helped the Tories surge in Scotland , mainly because she's not seen as a "traditional Tory".
She once said that LGBTI rights was the one thing she cares about more than her party, and she has referred to herself as a "kickboxing lesbian".
In October Davidson and her partner Jen Wilson welcomed baby boy called Finn after having IVF.
She shared a family photo on Twitter with the message: "Welcome to the world, little one.
"Finn Paul Davidson, born today, 10lb 1.5oz. Know that you are loved. X"
Davidson is also a fond of a bizarre photocall, and we've been treated to some memorable snaps over the years.
We've seen her sitting on a tank, riding a bull and even playing the bagpipes.
She also had a go in a penalty shoot out - and scored a goal.
Davidson's father Douglas was a midfielder for Partick Thistle and Selkirk FC in his younger days.
She studied English Literature at the University of Edinburgh, before working as a journalist for the BBC. She also served as a signaller in the Territorial Army.
Her hobbies include kickboxing and hill walking.
Despite becoming a popular member of the party, some of Davidson's decisions have caused outrage.
In 2017 she came under fire for refusing to condemn the "rape clause" on the child tax credit reform.
It requires woman who a third child through rape or during an abusive relationship to prove that is how the baby was conceived.
During a session in Scottish Parliament Nicola Sturgeon challenged on the "utterly abhorrent" policy.
Ms Davidson responded: "If the first minister doesn't like the two-child tax policy, she can change it."
This was met by shouts of "shame, shame" from fellow MSPs, and Ms Sturgeon replied: "Shame on Ruth Davidson and shame on the Conservatives."
Her election to leader of the Scottish party was also dogged by controversy, and there were rumours she was being helped along by the Tory HQ.
However she and her supporters strongly denied this, saying it was a smear campaign.
